diff --git a/BUILD b/BUILD
index 06c3f61e1d45b1cdf2afd5a34275a596d868da5f..659e79a1e0e6f9112c48e64ebf55570341c022b1 100644
--- a/BUILD
+++ b/BUILD
@@ -45,6 +45,7 @@ cc_library(
   name = "gpr",
   srcs = [
     "src/core/profiling/timers.h",
+    "src/core/support/backoff.h",
     "src/core/support/block_annotate.h",
     "src/core/support/env.h",
     "src/core/support/load_file.h",
@@ -59,6 +60,7 @@ cc_library(
     "src/core/profiling/stap_timers.c",
     "src/core/support/alloc.c",
     "src/core/support/avl.c",
+    "src/core/support/backoff.c",
     "src/core/support/cmdline.c",
     "src/core/support/cpu_iphone.c",
     "src/core/support/cpu_linux.c",
@@ -1233,6 +1235,7 @@ objc_library(
     "src/core/profiling/stap_timers.c",
     "src/core/support/alloc.c",
     "src/core/support/avl.c",
+    "src/core/support/backoff.c",
     "src/core/support/cmdline.c",
     "src/core/support/cpu_iphone.c",
     "src/core/support/cpu_linux.c",
@@ -1317,6 +1320,7 @@ objc_library(
     "include/grpc/impl/codegen/sync_win32.h",
     "include/grpc/impl/codegen/time.h",
     "src/core/profiling/timers.h",
+    "src/core/support/backoff.h",
     "src/core/support/block_annotate.h",
     "src/core/support/env.h",
     "src/core/support/load_file.h",
diff --git a/Makefile b/Makefile
index 0d6803121687cad7c19ed402e9ded26b1e448e57..9198e32dfb544379b3a3b7e5b06900c73edbbed9 100644
--- a/Makefile
+++ b/Makefile
@@ -893,6 +893,7 @@ fling_test: $(BINDIR)/$(CONFIG)/fling_test
 gen_hpack_tables: $(BINDIR)/$(CONFIG)/gen_hpack_tables
 gen_legal_metadata_characters: $(BINDIR)/$(CONFIG)/gen_legal_metadata_characters
 gpr_avl_test: $(BINDIR)/$(CONFIG)/gpr_avl_test
+gpr_backoff_test: $(BINDIR)/$(CONFIG)/gpr_backoff_test
 gpr_cmdline_test: $(BINDIR)/$(CONFIG)/gpr_cmdline_test
 gpr_cpu_test: $(BINDIR)/$(CONFIG)/gpr_cpu_test
 gpr_env_test: $(BINDIR)/$(CONFIG)/gpr_env_test
@@ -1204,6 +1205,7 @@ buildtests_c: privatelibs_c \
   $(BINDIR)/$(CONFIG)/fling_stream_test \
   $(BINDIR)/$(CONFIG)/fling_test \
   $(BINDIR)/$(CONFIG)/gpr_avl_test \
+  $(BINDIR)/$(CONFIG)/gpr_backoff_test \
   $(BINDIR)/$(CONFIG)/gpr_cmdline_test \
   $(BINDIR)/$(CONFIG)/gpr_cpu_test \
   $(BINDIR)/$(CONFIG)/gpr_env_test \
@@ -1458,6 +1460,8 @@ test_c: buildtests_c
 	$(Q) $(BINDIR)/$(CONFIG)/fling_test || ( echo test fling_test failed ; exit 1 )
 	$(E) "[RUN]     Testing gpr_avl_test"
 	$(Q) $(BINDIR)/$(CONFIG)/gpr_avl_test || ( echo test gpr_avl_test failed ; exit 1 )
+	$(E) "[RUN]     Testing gpr_backoff_test"
+	$(Q) $(BINDIR)/$(CONFIG)/gpr_backoff_test || ( echo test gpr_backoff_test failed ; exit 1 )
 	$(E) "[RUN]     Testing gpr_cmdline_test"
 	$(Q) $(BINDIR)/$(CONFIG)/gpr_cmdline_test || ( echo test gpr_cmdline_test failed ; exit 1 )
 	$(E) "[RUN]     Testing gpr_cpu_test"
@@ -1536,8 +1540,6 @@ test_c: buildtests_c
 	$(Q) $(BINDIR)/$(CONFIG)/json_test || ( echo test json_test failed ; exit 1 )
 	$(E) "[RUN]     Testing lame_client_test"
 	$(Q) $(BINDIR)/$(CONFIG)/lame_client_test || ( echo test lame_client_test failed ; exit 1 )
-	$(E) "[RUN]     Testing lb_policies_test"
-	$(Q) $(BINDIR)/$(CONFIG)/lb_policies_test || ( echo test lb_policies_test failed ; exit 1 )
 	$(E) "[RUN]     Testing message_compress_test"
 	$(Q) $(BINDIR)/$(CONFIG)/message_compress_test || ( echo test message_compress_test failed ; exit 1 )
 	$(E) "[RUN]     Testing mlog_test"
@@ -1619,6 +1621,8 @@ test_c: buildtests_c
 
 
 flaky_test_c: buildtests_c
+	$(E) "[RUN]     Testing lb_policies_test"
+	$(Q) $(BINDIR)/$(CONFIG)/lb_policies_test || ( echo test lb_policies_test failed ; exit 1 )
 
 
 test_cxx: test_zookeeper buildtests_cxx
@@ -2250,6 +2254,7 @@ LIBGPR_SRC = \
     src/core/profiling/stap_timers.c \
     src/core/support/alloc.c \
     src/core/support/avl.c \
+    src/core/support/backoff.c \
     src/core/support/cmdline.c \
     src/core/support/cpu_iphone.c \
     src/core/support/cpu_linux.c \
@@ -6621,6 +6626,38 @@ endif
 endif
 
 
+GPR_BACKOFF_TEST_SRC = \
+    test/core/support/backoff_test.c \
+
+GPR_BACKOFF_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(GPR_BACKOFF_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/gpr_backoff_test: openssl_dep_error
+
+else
+
+
+
+$(BINDIR)/$(CONFIG)/gpr_backoff_test: $(GPR_BACKOFF_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LD) $(LDFLAGS) $(GPR_BACKOFF_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBS) $(LDLIBS_SECURE) -o $(BINDIR)/$(CONFIG)/gpr_backoff_test
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/support/backoff_test.o:  $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+
+deps_gpr_backoff_test: $(GPR_BACKOFF_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(GPR_BACKOFF_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 GPR_CMDLINE_TEST_SRC = \
     test/core/support/cmdline_test.c \
 
diff --git a/binding.gyp b/binding.gyp
index d1e086cfa088771fca325ffed80fdd7efb43d573..bb974d6ef8a20cd480ec434fa1806978a9da2a48 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -496,6 +496,7 @@
         'src/core/profiling/stap_timers.c',
         'src/core/support/alloc.c',
         'src/core/support/avl.c',
+        'src/core/support/backoff.c',
         'src/core/support/cmdline.c',
         'src/core/support/cpu_iphone.c',
         'src/core/support/cpu_linux.c',
diff --git a/build.yaml b/build.yaml
index 5f61e18c0aae71f25cf39daa898c60399595e427..284e3e72ab7688675f65b563c4b615c02e56c14b 100644
--- a/build.yaml
+++ b/build.yaml
@@ -55,6 +55,7 @@ filegroups:
   - include/grpc/support/useful.h
   headers:
   - src/core/profiling/timers.h
+  - src/core/support/backoff.h
   - src/core/support/block_annotate.h
   - src/core/support/env.h
   - src/core/support/load_file.h
@@ -70,6 +71,7 @@ filegroups:
   - src/core/profiling/stap_timers.c
   - src/core/support/alloc.c
   - src/core/support/avl.c
+  - src/core/support/backoff.c
   - src/core/support/cmdline.c
   - src/core/support/cpu_iphone.c
   - src/core/support/cpu_linux.c
@@ -1239,6 +1241,14 @@ targets:
   deps:
   - gpr_test_util
   - gpr
+- name: gpr_backoff_test
+  build: test
+  language: c
+  src:
+  - test/core/support/backoff_test.c
+  deps:
+  - gpr_test_util
+  - gpr
 - name: gpr_cmdline_test
   build: test
   language: c
@@ -1663,6 +1673,7 @@ targets:
   - gpr
 - name: lb_policies_test
   cpu_cost: 0.1
+  flaky: true
   build: test
   language: c
   src:
@@ -2438,7 +2449,7 @@ targets:
   - linux
   - posix
 - name: qps_openloop_test
-  cpu_cost: 10
+  cpu_cost: 0.5
   build: test
   language: c++
   src:
diff --git a/config.m4 b/config.m4
index 8ab45e66037497824c90d62a0447412b525d17fb..013303838e047ed9a49f2994757603cabb0f81e2 100644
--- a/config.m4
+++ b/config.m4
@@ -40,6 +40,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/profiling/stap_timers.c \
     src/core/support/alloc.c \
     src/core/support/avl.c \
+    src/core/support/backoff.c \
     src/core/support/cmdline.c \
     src/core/support/cpu_iphone.c \
     src/core/support/cpu_linux.c \
diff --git a/gRPC.podspec b/gRPC.podspec
index 6f26db1ac1a9d658c0eac3e6fc3e516e49e26918..8a83bd23e2b3700579af64cd8cdfce2a0ee7c7d6 100644
--- a/gRPC.podspec
+++ b/gRPC.podspec
@@ -64,6 +64,7 @@ Pod::Spec.new do |s|
   # Core cross-platform gRPC library, written in C.
   s.subspec 'C-Core' do |ss|
     ss.source_files = 'src/core/profiling/timers.h',
+                      'src/core/support/backoff.h',
                       'src/core/support/block_annotate.h',
                       'src/core/support/env.h',
                       'src/core/support/load_file.h',
@@ -120,6 +121,7 @@ Pod::Spec.new do |s|
                       'src/core/profiling/stap_timers.c',
                       'src/core/support/alloc.c',
                       'src/core/support/avl.c',
+                      'src/core/support/backoff.c',
                       'src/core/support/cmdline.c',
                       'src/core/support/cpu_iphone.c',
                       'src/core/support/cpu_linux.c',
@@ -470,6 +472,7 @@ Pod::Spec.new do |s|
                       'third_party/nanopb/pb_encode.c'
 
     ss.private_header_files = 'src/core/profiling/timers.h',
+                              'src/core/support/backoff.h',
                               'src/core/support/block_annotate.h',
                               'src/core/support/env.h',
                               'src/core/support/load_file.h',
diff --git a/grpc.gemspec b/grpc.gemspec
index 0bc4fcfc0e4205dc6bf83051750346208c0638fe..4480c6e5d1bdf12cf42822cfb578e98d0b7efc7b 100755
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -89,6 +89,7 @@ Gem::Specification.new do |s|
   s.files += %w( include/grpc/impl/codegen/sync_win32.h )
   s.files += %w( include/grpc/impl/codegen/time.h )
   s.files += %w( src/core/profiling/timers.h )
+  s.files += %w( src/core/support/backoff.h )
   s.files += %w( src/core/support/block_annotate.h )
   s.files += %w( src/core/support/env.h )
   s.files += %w( src/core/support/load_file.h )
@@ -103,6 +104,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/profiling/stap_timers.c )
   s.files += %w( src/core/support/alloc.c )
   s.files += %w( src/core/support/avl.c )
+  s.files += %w( src/core/support/backoff.c )
   s.files += %w( src/core/support/cmdline.c )
   s.files += %w( src/core/support/cpu_iphone.c )
   s.files += %w( src/core/support/cpu_linux.c )
diff --git a/include/grpc++/impl/codegen/completion_queue_tag.h b/include/grpc++/impl/codegen/completion_queue_tag.h
index 8be2ac36d6e85e83211e7d827e7fdbb5446c35d2..e904f73e96258ff54181197c1c1d4dae7443bf96 100644
--- a/include/grpc++/impl/codegen/completion_queue_tag.h
+++ b/include/grpc++/impl/codegen/completion_queue_tag.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPCXX_COMPLETION_QUEUE_TAG_H
-#define GRPCXX_COMPLETION_QUEUE_TAG_H
+#ifndef GRPCXX_IMPL_CODEGEN_COMPLETION_QUEUE_TAG_H
+#define GRPCXX_IMPL_CODEGEN_COMPLETION_QUEUE_TAG_H
 
 namespace grpc {
 
@@ -49,4 +49,4 @@ class CompletionQueueTag {
 
 }  // namespace grpc
 
-#endif  // GRPCXX_COMPLETION_QUEUE_TAG_H
+#endif  // GRPCXX_IMPL_CODEGEN_COMPLETION_QUEUE_TAG_H
diff --git a/include/grpc++/impl/codegen/impl/async_stream.h b/include/grpc++/impl/codegen/impl/async_stream.h
index 8f9afe82510c18ba697c99197ffb8d452cd2cae2..413eab7570b951c6d10b4f3321fee101d539607f 100644
--- a/include/grpc++/impl/codegen/impl/async_stream.h
+++ b/include/grpc++/impl/codegen/impl/async_stream.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPCXX_IMPL_CODEGEN_ASYNC_STREAM_H
-#define GRPCXX_IMPL_CODEGEN_ASYNC_STREAM_H
+#ifndef GRPCXX_IMPL_CODEGEN_IMPL_ASYNC_STREAM_H
+#define GRPCXX_IMPL_CODEGEN_IMPL_ASYNC_STREAM_H
 
 #include <grpc++/impl/codegen/call.h>
 #include <grpc++/impl/codegen/channel_interface.h>
@@ -460,4 +460,4 @@ class ServerAsyncReaderWriter GRPC_FINAL : public ServerAsyncStreamingInterface,
 
 }  // namespace grpc
 
-#endif  // GRPCXX_IMPL_CODEGEN_ASYNC_STREAM_H
+#endif  // GRPCXX_IMPL_CODEGEN_IMPL_ASYNC_STREAM_H
diff --git a/include/grpc++/impl/codegen/impl/status_code_enum.h b/include/grpc++/impl/codegen/impl/status_code_enum.h
index 9a90a18e2a53305eab91737d757a605b89f0ad2f..f8caec0c119371ea9f569094331dced2772693e2 100644
--- a/include/grpc++/impl/codegen/impl/status_code_enum.h
+++ b/include/grpc++/impl/codegen/impl/status_code_enum.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPCXX_IMPL_CODEGEN_STATUS_CODE_ENUM_H
-#define GRPCXX_IMPL_CODEGEN_STATUS_CODE_ENUM_H
+#ifndef GRPCXX_IMPL_CODEGEN_IMPL_STATUS_CODE_ENUM_H
+#define GRPCXX_IMPL_CODEGEN_IMPL_STATUS_CODE_ENUM_H
 
 namespace grpc {
 
@@ -149,4 +149,4 @@ enum StatusCode {
 
 }  // namespace grpc
 
-#endif  // GRPCXX_IMPL_CODEGEN_STATUS_CODE_ENUM_H
+#endif  // GRPCXX_IMPL_CODEGEN_IMPL_STATUS_CODE_ENUM_H
diff --git a/include/grpc++/impl/codegen/impl/sync.h b/include/grpc++/impl/codegen/impl/sync.h
index 375af1543b882787a2ad630e0a893c4286f83e89..68fd0c4f2dc01440da30395cdd6ef498466908a9 100644
--- a/include/grpc++/impl/codegen/impl/sync.h
+++ b/include/grpc++/impl/codegen/impl/sync.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPCXX_IMPL_CODEGEN_SYNC_H
-#define GRPCXX_IMPL_CODEGEN_SYNC_H
+#ifndef GRPCXX_IMPL_CODEGEN_IMPL_SYNC_H
+#define GRPCXX_IMPL_CODEGEN_IMPL_SYNC_H
 
 #include <grpc++/impl/codegen/config.h>
 
@@ -42,4 +42,4 @@
 #include <grpc++/impl/codegen/sync_cxx11.h>
 #endif
 
-#endif  // GRPCXX_IMPL_CODEGEN_SYNC_H
+#endif  // GRPCXX_IMPL_CODEGEN_IMPL_SYNC_H
diff --git a/include/grpc++/impl/proto_utils.h b/include/grpc++/impl/proto_utils.h
index 9124001e207f0f8b9629de3464166a81044e93d0..36acabba799577ace80188ab52ecdab065bf0edd 100644
--- a/include/grpc++/impl/proto_utils.h
+++ b/include/grpc++/impl/proto_utils.h
@@ -31,9 +31,9 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CPP_PROTO_PROTO_UTILS_H
-#define GRPC_INTERNAL_CPP_PROTO_PROTO_UTILS_H
+#ifndef GRPCXX_IMPL_PROTO_UTILS_H
+#define GRPCXX_IMPL_PROTO_UTILS_H
 
 #include <grpc++/impl/codegen/proto_utils.h>
 
-#endif  // GRPC_INTERNAL_CPP_PROTO_PROTO_UTILS_H
+#endif  // GRPCXX_IMPL_PROTO_UTILS_H
diff --git a/include/grpc++/security/auth_context.h b/include/grpc++/security/auth_context.h
index bca8fa7c0ccb3562b3a3f7ba90bf3884761077aa..548f9a236c53e6970b125efef95bfe5ffd17d6e3 100644
--- a/include/grpc++/security/auth_context.h
+++ b/include/grpc++/security/auth_context.h
@@ -31,9 +31,9 @@
  *
  */
 
-#ifndef GRPCXX_SUPPORT_AUTH_CONTEXT_H
-#define GRPCXX_SUPPORT_AUTH_CONTEXT_H
+#ifndef GRPCXX_SECURITY_AUTH_CONTEXT_H
+#define GRPCXX_SECURITY_AUTH_CONTEXT_H
 
 #include <grpc++/impl/codegen/security/auth_context.h>
 
-#endif  // GRPCXX_SUPPORT_AUTH_CONTEXT_H
+#endif  // GRPCXX_SECURITY_AUTH_CONTEXT_H
diff --git a/include/grpc++/security/auth_metadata_processor.h b/include/grpc++/security/auth_metadata_processor.h
index 25011f33bafae0206d95f4f93dcdcc1a62d30fd1..b39451f83e350bb30837af33f34ac59ebee0a485 100644
--- a/include/grpc++/security/auth_metadata_processor.h
+++ b/include/grpc++/security/auth_metadata_processor.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPCXX_AUTH_METADATA_PROCESSOR_H_
-#define GRPCXX_AUTH_METADATA_PROCESSOR_H_
+#ifndef GRPCXX_SECURITY_AUTH_METADATA_PROCESSOR_H
+#define GRPCXX_SECURITY_AUTH_METADATA_PROCESSOR_H
 
 #include <map>
 
@@ -70,4 +70,4 @@ class AuthMetadataProcessor {
 
 }  // namespace grpc
 
-#endif  // GRPCXX_AUTH_METADATA_PROCESSOR_H_
+#endif  // GRPCXX_SECURITY_AUTH_METADATA_PROCESSOR_H
diff --git a/include/grpc++/security/credentials.h b/include/grpc++/security/credentials.h
index f2e2efd7a6eba7048c50da896ab1f8c55db8ba44..bedfc9c2a227b5e71244b5866e7497bd78f7a2f2 100644
--- a/include/grpc++/security/credentials.h
+++ b/include/grpc++/security/credentials.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPCXX_CREDENTIALS_H
-#define GRPCXX_CREDENTIALS_H
+#ifndef GRPCXX_SECURITY_CREDENTIALS_H
+#define GRPCXX_SECURITY_CREDENTIALS_H
 
 #include <map>
 #include <memory>
@@ -229,4 +229,4 @@ std::shared_ptr<CallCredentials> MetadataCredentialsFromPlugin(
 
 }  // namespace grpc
 
-#endif  // GRPCXX_CREDENTIALS_H
+#endif  // GRPCXX_SECURITY_CREDENTIALS_H
diff --git a/include/grpc++/security/server_credentials.h b/include/grpc++/security/server_credentials.h
index e933825ec37977ab5b8c8e14158c525662f493cc..addb11ccb460a04f2ec158b8ea4d8be752f9899b 100644
--- a/include/grpc++/security/server_credentials.h
+++ b/include/grpc++/security/server_credentials.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPCXX_SERVER_CREDENTIALS_H
-#define GRPCXX_SERVER_CREDENTIALS_H
+#ifndef GRPCXX_SECURITY_SERVER_CREDENTIALS_H
+#define GRPCXX_SECURITY_SERVER_CREDENTIALS_H
 
 #include <memory>
 #include <vector>
@@ -89,4 +89,4 @@ std::shared_ptr<ServerCredentials> InsecureServerCredentials();
 
 }  // namespace grpc
 
-#endif  // GRPCXX_SERVER_CREDENTIALS_H
+#endif  // GRPCXX_SECURITY_SERVER_CREDENTIALS_H
diff --git a/include/grpc/census.h b/include/grpc/census.h
index 442a754f0a45f32e09fb7ba25873077c9139b454..4ccf4af5fe54324d8a641efe58baa7bd6a961752 100644
--- a/include/grpc/census.h
+++ b/include/grpc/census.h
@@ -35,8 +35,8 @@
  * they can (ultimately) be used in many different RPC systems (with differing
  * implementations). */
 
-#ifndef CENSUS_CENSUS_H
-#define CENSUS_CENSUS_H
+#ifndef GRPC_CENSUS_H
+#define GRPC_CENSUS_H
 
 #include <grpc/grpc.h>
 
@@ -537,4 +537,4 @@ CENSUSAPI void census_view_reset(census_view *view);
 }
 #endif
 
-#endif /* CENSUS_CENSUS_H */
+#endif /* GRPC_CENSUS_H */
diff --git a/include/grpc/impl/codegen/propagation_bits.h b/include/grpc/impl/codegen/propagation_bits.h
index cdd699710c2378bd205975f2abfd71c04f57250d..4b6455876483d5b11b0f54a115afe7ae15ad1504 100644
--- a/include/grpc/impl/codegen/propagation_bits.h
+++ b/include/grpc/impl/codegen/propagation_bits.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_IMPL_CODEGEN_H
-#define GRPC_IMPL_CODEGEN_H
+#ifndef GRPC_IMPL_CODEGEN_PROPAGATION_BITS_H
+#define GRPC_IMPL_CODEGEN_PROPAGATION_BITS_H
 
 #include <grpc/impl/codegen/port_platform.h>
 
@@ -64,4 +64,4 @@ extern "C" {
 }
 #endif
 
-#endif /* GRPC_IMPL_CODEGEN_H */
+#endif /* GRPC_IMPL_CODEGEN_PROPAGATION_BITS_H */
diff --git a/include/grpc/support/atm_gcc_atomic.h b/include/grpc/support/atm_gcc_atomic.h
index 7e1f7fd55a575b991d7945aeb532acdc23a6f43c..2fc8f609a5af64d0e1c12a8f1a28c07d3422a2d5 100644
--- a/include/grpc/support/atm_gcc_atomic.h
+++ b/include/grpc/support/atm_gcc_atomic.h
@@ -31,9 +31,9 @@
  *
  */
 
-#ifndef GRPC_IMPL_CODEGEN_ATM_GCC_ATOMIC_H
-#define GRPC_IMPL_CODEGEN_ATM_GCC_ATOMIC_H
+#ifndef GRPC_SUPPORT_ATM_GCC_ATOMIC_H
+#define GRPC_SUPPORT_ATM_GCC_ATOMIC_H
 
 #include <grpc/impl/codegen/atm_gcc_atomic.h>
 
-#endif /* GRPC_IMPL_CODEGEN_ATM_GCC_ATOMIC_H */
+#endif /* GRPC_SUPPORT_ATM_GCC_ATOMIC_H */
diff --git a/include/grpc/support/subprocess.h b/include/grpc/support/subprocess.h
index 6a4946014bed5bee01cccf76af4a5c69fba8257f..e013b706ec024b67415861500d99d711efae9ff4 100644
--- a/include/grpc/support/subprocess.h
+++ b/include/grpc/support/subprocess.h
@@ -56,4 +56,4 @@ GPRAPI void gpr_subprocess_interrupt(gpr_subprocess *p);
 }  // extern "C"
 #endif
 
-#endif
+#endif /* GRPC_SUPPORT_SUBPROCESS_H */
diff --git a/include/grpc/support/tls.h b/include/grpc/support/tls.h
index 43addc7f14556c8cb2832591b8eed4e9f5a77ca6..0ff19bbaddd14ea891a4ecf8786cb7a6f8a3be5f 100644
--- a/include/grpc/support/tls.h
+++ b/include/grpc/support/tls.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -74,4 +74,4 @@
 #include <grpc/support/tls_pthread.h>
 #endif
 
-#endif
+#endif /* GRPC_SUPPORT_TLS_H */
diff --git a/include/grpc/support/tls_gcc.h b/include/grpc/support/tls_gcc.h
index 5aebe6ded977a29076774edad07f5c96c3a1bf0f..21269e4b141b35f4372e3f053ff8cbe528274580 100644
--- a/include/grpc/support/tls_gcc.h
+++ b/include/grpc/support/tls_gcc.h
@@ -97,4 +97,4 @@ struct gpr_gcc_thread_local {
 
 #endif /* NDEBUG */
 
-#endif
+#endif /* GRPC_SUPPORT_TLS_GCC_H */
diff --git a/include/grpc/support/tls_msvc.h b/include/grpc/support/tls_msvc.h
index 987a514f0371c6661516f425b5a74350f833cb84..751ec35f73b0c3742db55b428d5b34b183d07334 100644
--- a/include/grpc/support/tls_msvc.h
+++ b/include/grpc/support/tls_msvc.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_SUPPORT_TLS_GCC_H
-#define GRPC_SUPPORT_TLS_GCC_H
+#ifndef GRPC_SUPPORT_TLS_MSVC_H
+#define GRPC_SUPPORT_TLS_MSVC_H
 
 /* Thread local storage based on ms visual c compiler primitives.
    #include tls.h to use this - and see that file for documentation */
@@ -53,4 +53,4 @@ struct gpr_msvc_thread_local {
 #define gpr_tls_set(tls, new_value) (((tls)->value) = (new_value))
 #define gpr_tls_get(tls) ((tls)->value)
 
-#endif
+#endif /* GRPC_SUPPORT_TLS_MSVC_H */
diff --git a/include/grpc/support/tls_pthread.h b/include/grpc/support/tls_pthread.h
index 699ee6b1d382c3c481b8f4e8d954546a9f52d27a..93ba7822c3a2655cf0c39523bc9b65216c84f7a1 100644
--- a/include/grpc/support/tls_pthread.h
+++ b/include/grpc/support/tls_pthread.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -57,4 +57,4 @@ intptr_t gpr_tls_set(struct gpr_pthread_thread_local *tls, intptr_t value);
 }
 #endif
 
-#endif
+#endif /* GRPC_SUPPORT_TLS_PTHREAD_H */
diff --git a/package.json b/package.json
index e52a283d9d4e7d1de834ffc57b98ded950c7528c..cd9668a1b0e2b6c8e295107d384810112e6a8da3 100644
--- a/package.json
+++ b/package.json
@@ -865,6 +865,7 @@
     "include/grpc/impl/codegen/sync_win32.h",
     "include/grpc/impl/codegen/time.h",
     "src/core/profiling/timers.h",
+    "src/core/support/backoff.h",
     "src/core/support/block_annotate.h",
     "src/core/support/env.h",
     "src/core/support/load_file.h",
@@ -879,6 +880,7 @@
     "src/core/profiling/stap_timers.c",
     "src/core/support/alloc.c",
     "src/core/support/avl.c",
+    "src/core/support/backoff.c",
     "src/core/support/cmdline.c",
     "src/core/support/cpu_iphone.c",
     "src/core/support/cpu_linux.c",
diff --git a/package.xml b/package.xml
index da06e90e3b8faa96dbb27608bab4273beea75722..1e0bbc7e39747fb1324dc09a643f02298367bb9b 100644
--- a/package.xml
+++ b/package.xml
@@ -93,6 +93,7 @@
     <file baseinstalldir="/" name="include/grpc/impl/codegen/sync_win32.h" role="src" />
     <file baseinstalldir="/" name="include/grpc/impl/codegen/time.h" role="src" />
     <file baseinstalldir="/" name="src/core/profiling/timers.h" role="src" />
+    <file baseinstalldir="/" name="src/core/support/backoff.h" role="src" />
     <file baseinstalldir="/" name="src/core/support/block_annotate.h" role="src" />
     <file baseinstalldir="/" name="src/core/support/env.h" role="src" />
     <file baseinstalldir="/" name="src/core/support/load_file.h" role="src" />
@@ -107,6 +108,7 @@
     <file baseinstalldir="/" name="src/core/profiling/stap_timers.c" role="src" />
     <file baseinstalldir="/" name="src/core/support/alloc.c" role="src" />
     <file baseinstalldir="/" name="src/core/support/avl.c" role="src" />
+    <file baseinstalldir="/" name="src/core/support/backoff.c" role="src" />
     <file baseinstalldir="/" name="src/core/support/cmdline.c" role="src" />
     <file baseinstalldir="/" name="src/core/support/cpu_iphone.c" role="src" />
     <file baseinstalldir="/" name="src/core/support/cpu_linux.c" role="src" />
diff --git a/setup.py b/setup.py
index 45ff2cec89b1f93007be535776e4d14f51c04451..afa9872ff24d01931d7447db463fcfb7f9119c1c 100644
--- a/setup.py
+++ b/setup.py
@@ -42,6 +42,7 @@ from setuptools.command import egg_info
 # Redirect the manifest template from MANIFEST.in to PYTHON-MANIFEST.in.
 egg_info.manifest_maker.template = 'PYTHON-MANIFEST.in'
 
+PY3 = sys.version_info.major == 3
 PYTHON_STEM = './src/python/grpcio'
 CORE_INCLUDE = ('./include', '.',)
 BORINGSSL_INCLUDE = ('./third_party/boringssl/include',)
@@ -103,7 +104,11 @@ if "linux" in sys.platform:
   LDFLAGS += ('-Wl,-wrap,memcpy',)
 if "linux" in sys.platform or "darwin" in sys.platform:
   CFLAGS += ('-fvisibility=hidden',)
-  DEFINE_MACROS += (('PyMODINIT_FUNC', '__attribute__((visibility ("default"))) void'),)
+
+  pymodinit_type = 'PyObject*' if PY3 else 'void'
+
+  pymodinit = '__attribute__((visibility ("default"))) {}'.format(pymodinit_type)
+  DEFINE_MACROS += (('PyMODINIT_FUNC', pymodinit),)
 
 
 def cython_extensions(package_names, module_names, extra_sources, include_dirs,
diff --git a/src/core/census/aggregation.h b/src/core/census/aggregation.h
index e9bc6ada96085b9c80953773129907e89071bd77..e0ef9630c929d4f7355abefcb830e0a37df04698 100644
--- a/src/core/census/aggregation.h
+++ b/src/core/census/aggregation.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -33,8 +33,8 @@
 
 #include <stddef.h>
 
-#ifndef GRPC_INTERNAL_CORE_CENSUS_AGGREGATION_H
-#define GRPC_INTERNAL_CORE_CENSUS_AGGREGATION_H
+#ifndef GRPC_CORE_CENSUS_AGGREGATION_H
+#define GRPC_CORE_CENSUS_AGGREGATION_H
 
 /** Structure used to describe an aggregation type. */
 struct census_aggregation_ops {
@@ -63,4 +63,4 @@ struct census_aggregation_ops {
   size_t (*print)(const void *aggregation, char *buffer, size_t n);
 };
 
-#endif /* GRPC_INTERNAL_CORE_CENSUS_AGGREGATION_H */
+#endif /* GRPC_CORE_CENSUS_AGGREGATION_H */
diff --git a/src/core/census/grpc_filter.h b/src/core/census/grpc_filter.h
index b3de3adc94761a4ed6d565d284c6f570fb0e02c3..4699e4d692735a09677d647107d9aca96221ca56 100644
--- a/src/core/census/grpc_filter.h
+++ b/src/core/census/grpc_filter.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CENSUS_GRPC_FILTER_H
-#define GRPC_INTERNAL_CORE_CENSUS_GRPC_FILTER_H
+#ifndef GRPC_CORE_CENSUS_GRPC_FILTER_H
+#define GRPC_CORE_CENSUS_GRPC_FILTER_H
 
 #include "src/core/channel/channel_stack.h"
 
@@ -41,4 +41,4 @@
 extern const grpc_channel_filter grpc_client_census_filter;
 extern const grpc_channel_filter grpc_server_census_filter;
 
-#endif /* GRPC_INTERNAL_CORE_CENSUS_GRPC_FILTER_H */
+#endif /* GRPC_CORE_CENSUS_GRPC_FILTER_H */
diff --git a/src/core/census/mlog.h b/src/core/census/mlog.h
index aaba9e15356223b466b97f32de4af96fd17ec71f..bc6eaeaf2826d59b0519de4298d5aa00aa0a849e 100644
--- a/src/core/census/mlog.h
+++ b/src/core/census/mlog.h
@@ -33,8 +33,8 @@
 
 /* A very fast in-memory log, optimized for multiple writers. */
 
-#ifndef GRPC_INTERNAL_CORE_CENSUS_MLOG_H
-#define GRPC_INTERNAL_CORE_CENSUS_MLOG_H
+#ifndef GRPC_CORE_CENSUS_MLOG_H
+#define GRPC_CORE_CENSUS_MLOG_H
 
 #include <grpc/support/port_platform.h>
 #include <stddef.h>
@@ -92,4 +92,4 @@ size_t census_log_remaining_space(void);
    out-of-space. */
 int64_t census_log_out_of_space_count(void);
 
-#endif /* GRPC_INTERNAL_CORE_CENSUS_LOG_H */
+#endif /* GRPC_CORE_CENSUS_MLOG_H */
diff --git a/src/core/census/rpc_metric_id.h b/src/core/census/rpc_metric_id.h
index f199839511ce128ffd0311fa42c7ffd1ea944dff..f8d8dad0bf3da68b12789717ed1ee59fba81fc8a 100644
--- a/src/core/census/rpc_metric_id.h
+++ b/src/core/census/rpc_metric_id.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef CENSUS_RPC_METRIC_ID_H
-#define CENSUS_RPC_METRIC_ID_H
+#ifndef GRPC_CORE_CENSUS_RPC_METRIC_ID_H
+#define GRPC_CORE_CENSUS_RPC_METRIC_ID_H
 
 /* Metric ID's used for RPC measurements. */
 /* Count of client requests sent. */
@@ -48,4 +48,4 @@
 /* Server side request latency. */
 #define CENSUS_METRIC_RPC_SERVER_LATENCY ((uint32_t)5)
 
-#endif /* CENSUS_RPC_METRIC_ID_H */
+#endif /* GRPC_CORE_CENSUS_RPC_METRIC_ID_H */
diff --git a/src/core/channel/channel_args.h b/src/core/channel/channel_args.h
index b3a7c9f43492455b4086a7b0dcc5a313ece7e558..e19440f76fe93131d83d464feb51c4628dfd0337 100644
--- a/src/core/channel/channel_args.h
+++ b/src/core/channel/channel_args.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_ARGS_H
-#define GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_ARGS_H
+#ifndef GRPC_CORE_CHANNEL_CHANNEL_ARGS_H
+#define GRPC_CORE_CHANNEL_CHANNEL_ARGS_H
 
 #include <grpc/compression.h>
 #include <grpc/grpc.h>
@@ -91,4 +91,4 @@ int grpc_channel_args_compression_algorithm_get_states(
 int grpc_channel_args_compare(const grpc_channel_args *a,
                               const grpc_channel_args *b);
 
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_ARGS_H */
+#endif /* GRPC_CORE_CHANNEL_CHANNEL_ARGS_H */
diff --git a/src/core/channel/channel_stack.h b/src/core/channel/channel_stack.h
index c01050e7179aacd982e079c6d2e5c2910a8c27f9..52362f0b20e12c825fcd2b4f2659ccc7f5931aea 100644
--- a/src/core/channel/channel_stack.h
+++ b/src/core/channel/channel_stack.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_STACK_H
-#define GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_STACK_H
+#ifndef GRPC_CORE_CHANNEL_CHANNEL_STACK_H
+#define GRPC_CORE_CHANNEL_CHANNEL_STACK_H
 
 /* A channel filter defines how operations on a channel are implemented.
    Channel filters are chained together to create full channels, and if those
@@ -257,4 +257,4 @@ extern int grpc_trace_channel;
 #define GRPC_CALL_LOG_OP(sev, elem, op) \
   if (grpc_trace_channel) grpc_call_log_op(sev, elem, op)
 
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_STACK_H */
+#endif /* GRPC_CORE_CHANNEL_CHANNEL_STACK_H */
diff --git a/src/core/channel/client_channel.h b/src/core/channel/client_channel.h
index d9bc4971f1ae51837b858186982e62d3f58815a3..422f7f83749b79c2eee9c7630c7e1a24bbf3f458 100644
--- a/src/core/channel/client_channel.h
+++ b/src/core/channel/client_channel.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_CLIENT_CHANNEL_H
-#define GRPC_INTERNAL_CORE_CHANNEL_CLIENT_CHANNEL_H
+#ifndef GRPC_CORE_CHANNEL_CLIENT_CHANNEL_H
+#define GRPC_CORE_CHANNEL_CLIENT_CHANNEL_H
 
 #include "src/core/channel/channel_stack.h"
 #include "src/core/client_config/resolver.h"
@@ -60,4 +60,4 @@ void grpc_client_channel_watch_connectivity_state(
     grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, grpc_pollset *pollset,
     grpc_connectivity_state *state, grpc_closure *on_complete);
 
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_CLIENT_CHANNEL_H */
+#endif /* GRPC_CORE_CHANNEL_CLIENT_CHANNEL_H */
diff --git a/src/core/channel/client_uchannel.h b/src/core/channel/client_uchannel.h
index 92a831493cfbf7625850c3da82b930bcc72ac01e..8bb288e7d460e93fcfb040f73b990bab8b6b7101 100644
--- a/src/core/channel/client_uchannel.h
+++ b/src/core/channel/client_uchannel.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_CLIENT_MICROCHANNEL_H
-#define GRPC_INTERNAL_CORE_CHANNEL_CLIENT_MICROCHANNEL_H
+#ifndef GRPC_CORE_CHANNEL_CLIENT_UCHANNEL_H
+#define GRPC_CORE_CHANNEL_CLIENT_UCHANNEL_H
 
 #include "src/core/channel/channel_stack.h"
 #include "src/core/client_config/resolver.h"
@@ -57,4 +57,4 @@ grpc_channel *grpc_client_uchannel_create(grpc_subchannel *subchannel,
 void grpc_client_uchannel_set_connected_subchannel(
     grpc_channel *uchannel, grpc_connected_subchannel *connected_subchannel);
 
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_CLIENT_MICROCHANNEL_H */
+#endif /* GRPC_CORE_CHANNEL_CLIENT_UCHANNEL_H */
diff --git a/src/core/channel/compress_filter.h b/src/core/channel/compress_filter.h
index 415459bca60991261a74e09b099119a2bf7242b4..8c208ac799dacff3f0cc7913910689c78bfe2b4b 100644
--- a/src/core/channel/compress_filter.h
+++ b/src/core/channel/compress_filter.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_COMPRESS_FILTER_H
-#define GRPC_INTERNAL_CORE_CHANNEL_COMPRESS_FILTER_H
+#ifndef GRPC_CORE_CHANNEL_COMPRESS_FILTER_H
+#define GRPC_CORE_CHANNEL_COMPRESS_FILTER_H
 
 #include "src/core/channel/channel_stack.h"
 
@@ -62,4 +62,4 @@
 
 extern const grpc_channel_filter grpc_compress_filter;
 
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_COMPRESS_FILTER_H */
+#endif /* GRPC_CORE_CHANNEL_COMPRESS_FILTER_H */
diff --git a/src/core/channel/connected_channel.h b/src/core/channel/connected_channel.h
index 95c1834bfaab498bc10c6dbf4b8b14d6901d993d..7978ab3b80e53ac2c9481566bbe192350a4c88be 100644
--- a/src/core/channel/connected_channel.h
+++ b/src/core/channel/connected_channel.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_CONNECTED_CHANNEL_H
-#define GRPC_INTERNAL_CORE_CHANNEL_CONNECTED_CHANNEL_H
+#ifndef GRPC_CORE_CHANNEL_CONNECTED_CHANNEL_H
+#define GRPC_CORE_CHANNEL_CONNECTED_CHANNEL_H
 
 #include "src/core/channel/channel_stack.h"
 
@@ -48,4 +48,4 @@ void grpc_connected_channel_bind_transport(grpc_channel_stack* channel_stack,
 
 grpc_stream* grpc_connected_channel_get_stream(grpc_call_element* elem);
 
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_CONNECTED_CHANNEL_H */
+#endif /* GRPC_CORE_CHANNEL_CONNECTED_CHANNEL_H */
diff --git a/src/core/channel/context.h b/src/core/channel/context.h
index ac5796b9ef19fce5968790a791d56c0e86708dc3..db217dc133d8bb9512a4d29400143d061e0700d3 100644
--- a/src/core/channel/context.h
+++ b/src/core/channel/context.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_CONTEXT_H
-#define GRPC_INTERNAL_CORE_CHANNEL_CONTEXT_H
+#ifndef GRPC_CORE_CHANNEL_CONTEXT_H
+#define GRPC_CORE_CHANNEL_CONTEXT_H
 
 /* Call object context pointers */
 typedef enum {
@@ -46,4 +46,4 @@ typedef struct {
   void (*destroy)(void *);
 } grpc_call_context_element;
 
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_CONTEXT_H */
+#endif /* GRPC_CORE_CHANNEL_CONTEXT_H */
diff --git a/src/core/channel/http_client_filter.h b/src/core/channel/http_client_filter.h
index 21c66b9b8ee758aa9a3851d10b6e1f7375f397c7..6f619bbf0028d41568f54ab71c3aade6cc3ad8ce 100644
--- a/src/core/channel/http_client_filter.h
+++ b/src/core/channel/http_client_filter.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_HTTP_CLIENT_FILTER_H
-#define GRPC_INTERNAL_CORE_CHANNEL_HTTP_CLIENT_FILTER_H
+#ifndef GRPC_CORE_CHANNEL_HTTP_CLIENT_FILTER_H
+#define GRPC_CORE_CHANNEL_HTTP_CLIENT_FILTER_H
 
 #include "src/core/channel/channel_stack.h"
 
@@ -41,4 +41,4 @@ extern const grpc_channel_filter grpc_http_client_filter;
 
 #define GRPC_ARG_HTTP2_SCHEME "grpc.http2_scheme"
 
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_HTTP_CLIENT_FILTER_H */
+#endif /* GRPC_CORE_CHANNEL_HTTP_CLIENT_FILTER_H */
diff --git a/src/core/channel/http_server_filter.h b/src/core/channel/http_server_filter.h
index f219d4e66f38724c2143c3fb46f2f081ffff02a2..528c8648fde13ad3584727f23f758b4ce9eafac6 100644
--- a/src/core/channel/http_server_filter.h
+++ b/src/core/channel/http_server_filter.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_HTTP_SERVER_FILTER_H
-#define GRPC_INTERNAL_CORE_CHANNEL_HTTP_SERVER_FILTER_H
+#ifndef GRPC_CORE_CHANNEL_HTTP_SERVER_FILTER_H
+#define GRPC_CORE_CHANNEL_HTTP_SERVER_FILTER_H
 
 #include "src/core/channel/channel_stack.h"
 
 /* Processes metadata on the client side for HTTP2 transports */
 extern const grpc_channel_filter grpc_http_server_filter;
 
-#endif /* GRPC_INTERNAL_CORE_CHANNEL_HTTP_SERVER_FILTER_H */
+#endif /* GRPC_CORE_CHANNEL_HTTP_SERVER_FILTER_H */
diff --git a/src/core/channel/subchannel_call_holder.h b/src/core/channel/subchannel_call_holder.h
index 9cf72c6cf76a1cb0e9284f0f2f92097e2eb33549..9086cdc882a2a11291681ab2dfb4312d263f6274 100644
--- a/src/core/channel/subchannel_call_holder.h
+++ b/src/core/channel/subchannel_call_holder.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHANNEL_SUBCHANNEL_CALL_HOLDER_H
-#define GRPC_INTERNAL_CORE_CHANNEL_SUBCHANNEL_CALL_HOLDER_H
+#ifndef GRPC_CORE_CHANNEL_SUBCHANNEL_CALL_HOLDER_H
+#define GRPC_CORE_CHANNEL_SUBCHANNEL_CALL_HOLDER_H
 
 #include "src/core/client_config/subchannel.h"
 
@@ -95,4 +95,4 @@ void grpc_subchannel_call_holder_perform_op(grpc_exec_ctx *exec_ctx,
 char *grpc_subchannel_call_holder_get_peer(grpc_exec_ctx *exec_ctx,
                                            grpc_subchannel_call_holder *holder);
 
-#endif
+#endif /* GRPC_CORE_CHANNEL_SUBCHANNEL_CALL_HOLDER_H */
diff --git a/src/core/client_config/client_config.h b/src/core/client_config/client_config.h
index 04bf036b00b7e411b4dd334d7a3a649f76ada26c..9b37fdc2116fa78a16e0bd1886da0406be78db43 100644
--- a/src/core/client_config/client_config.h
+++ b/src/core/client_config/client_config.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_CLIENT_CONFIG_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_CLIENT_CONFIG_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_CLIENT_CONFIG_H
+#define GRPC_CORE_CLIENT_CONFIG_CLIENT_CONFIG_H
 
 #include "src/core/client_config/lb_policy.h"
 
@@ -50,4 +50,4 @@ void grpc_client_config_set_lb_policy(grpc_client_config *client_config,
 grpc_lb_policy *grpc_client_config_get_lb_policy(
     grpc_client_config *client_config);
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_CLIENT_CONFIG_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_CLIENT_CONFIG_H */
diff --git a/src/core/client_config/connector.h b/src/core/client_config/connector.h
index b91eb512c3016e9a855209a70a24ad252fc29b82..953ab96eb2962b50623a492db61ded5dcb8b5cd5 100644
--- a/src/core/client_config/connector.h
+++ b/src/core/client_config/connector.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_CONNECTOR_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_CONNECTOR_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_CONNECTOR_H
+#define GRPC_CORE_CLIENT_CONFIG_CONNECTOR_H
 
 #include "src/core/channel/channel_stack.h"
 #include "src/core/iomgr/sockaddr.h"
@@ -92,4 +92,4 @@ void grpc_connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
 void grpc_connector_shutdown(grpc_exec_ctx *exec_ctx,
                              grpc_connector *connector);
 
-#endif
+#endif /* GRPC_CORE_CLIENT_CONFIG_CONNECTOR_H */
diff --git a/src/core/client_config/initial_connect_string.h b/src/core/client_config/initial_connect_string.h
index b6dca7134a4345cc0c0989abe56f88c72442d7d3..e6d2d8f8fef754ad01493c5950a8053fb54e65cd 100644
--- a/src/core/client_config/initial_connect_string.h
+++ b/src/core/client_config/initial_connect_string.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
+#define GRPC_CORE_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
 
 #include <grpc/support/slice.h>
 #include "src/core/iomgr/sockaddr.h"
@@ -47,4 +47,4 @@ void grpc_test_set_initial_connect_string_function(
 void grpc_set_initial_connect_string(struct sockaddr **addr, size_t *addr_len,
                                      gpr_slice *connect_string);
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H */
diff --git a/src/core/client_config/lb_policies/load_balancer_api.h b/src/core/client_config/lb_policies/load_balancer_api.h
index 4dbe1d6c224ef595fe82cf3812c25f0293ae78c9..b7a4c9c8f5bb280c14552fdf8eefb879ba9de949 100644
--- a/src/core/client_config/lb_policies/load_balancer_api.h
+++ b/src/core/client_config/lb_policies/load_balancer_api.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H
+#define GRPC_CORE_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H
 
 #include <grpc/support/slice_buffer.h>
 
@@ -82,4 +82,4 @@ void grpc_grpclb_response_destroy(grpc_grpclb_response *response);
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H */
diff --git a/src/core/client_config/lb_policies/pick_first.h b/src/core/client_config/lb_policies/pick_first.h
index 3ca53ad42afa8c774c0187fb817abc7d6293ebb0..3a3f195df52a57e45e103684087f795341a9bcb6 100644
--- a/src/core/client_config/lb_policies/pick_first.h
+++ b/src/core/client_config/lb_policies/pick_first.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_PICK_FIRST_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_PICK_FIRST_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_LB_POLICIES_PICK_FIRST_H
+#define GRPC_CORE_CLIENT_CONFIG_LB_POLICIES_PICK_FIRST_H
 
 #include "src/core/client_config/lb_policy_factory.h"
 
@@ -40,4 +40,4 @@
  * the first subchannel from \a subchannels to succesfully connect */
 grpc_lb_policy_factory *grpc_pick_first_lb_factory_create();
 
-#endif
+#endif /* GRPC_CORE_CLIENT_CONFIG_LB_POLICIES_PICK_FIRST_H */
diff --git a/src/core/client_config/lb_policies/round_robin.h b/src/core/client_config/lb_policies/round_robin.h
index cf1f69c85f6dca3ef345110aeba35e23275be24e..7e6f1769e487adead97a615392d38af192fcb8ba 100644
--- a/src/core/client_config/lb_policies/round_robin.h
+++ b/src/core/client_config/lb_policies/round_robin.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_ROUND_ROBIN_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_ROUND_ROBIN_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_LB_POLICIES_ROUND_ROBIN_H
+#define GRPC_CORE_CLIENT_CONFIG_LB_POLICIES_ROUND_ROBIN_H
 
 #include "src/core/client_config/lb_policy.h"
 
@@ -43,4 +43,4 @@ extern int grpc_lb_round_robin_trace;
 /** Returns a load balancing factory for the round robin policy */
 grpc_lb_policy_factory *grpc_round_robin_lb_factory_create();
 
-#endif
+#endif /* GRPC_CORE_CLIENT_CONFIG_LB_POLICIES_ROUND_ROBIN_H */
diff --git a/src/core/client_config/lb_policy.h b/src/core/client_config/lb_policy.h
index 345739060682c0fb96fbd7f41c81a00546ab84b2..ffebc2a69ca14b2590cdfb6dbe60a51381fdd76d 100644
--- a/src/core/client_config/lb_policy.h
+++ b/src/core/client_config/lb_policy.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_LB_POLICY_H
+#define GRPC_CORE_CLIENT_CONFIG_LB_POLICY_H
 
 #include "src/core/client_config/subchannel.h"
 #include "src/core/transport/connectivity_state.h"
@@ -141,4 +141,4 @@ void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx,
 grpc_connectivity_state grpc_lb_policy_check_connectivity(
     grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
 
-#endif /* GRPC_INTERNAL_CORE_CONFIG_LB_POLICY_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_LB_POLICY_H */
diff --git a/src/core/client_config/lb_policy_factory.h b/src/core/client_config/lb_policy_factory.h
index 04610316ee4300bed4b5bfa1804928d2366a44fe..842ba9609865c24ce019f13aa4cf1de51cf659dd 100644
--- a/src/core/client_config/lb_policy_factory.h
+++ b/src/core/client_config/lb_policy_factory.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_FACTORY_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_FACTORY_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_LB_POLICY_FACTORY_H
+#define GRPC_CORE_CLIENT_CONFIG_LB_POLICY_FACTORY_H
 
 #include "src/core/client_config/lb_policy.h"
 #include "src/core/client_config/subchannel.h"
@@ -70,4 +70,4 @@ void grpc_lb_policy_factory_unref(grpc_lb_policy_factory *factory);
 grpc_lb_policy *grpc_lb_policy_factory_create_lb_policy(
     grpc_lb_policy_factory *factory, grpc_lb_policy_args *args);
 
-#endif /* GRPC_INTERNAL_CORE_CONFIG_LB_POLICY_FACTORY_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_LB_POLICY_FACTORY_H */
diff --git a/src/core/client_config/lb_policy_registry.h b/src/core/client_config/lb_policy_registry.h
index 96fc2a162851371def9028ebfbe61f89be6e553e..f3a08a3558bd3f21b5a15c65d1dfafdf83a653d4 100644
--- a/src/core/client_config/lb_policy_registry.h
+++ b/src/core/client_config/lb_policy_registry.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
+#define GRPC_CORE_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
 
 #include "src/core/client_config/lb_policy_factory.h"
 
@@ -51,4 +51,4 @@ void grpc_register_lb_policy(grpc_lb_policy_factory *factory);
 grpc_lb_policy *grpc_lb_policy_create(const char *name,
                                       grpc_lb_policy_args *args);
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_LB_POLICY_REGISTRY_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_LB_POLICY_REGISTRY_H */
diff --git a/src/core/client_config/resolver.h b/src/core/client_config/resolver.h
index e612eaf3b3cacddd942203d72fbd4ab114f2b0c5..96f88fef84dd46077421bf50a33cbd4b912f376f 100644
--- a/src/core/client_config/resolver.h
+++ b/src/core/client_config/resolver.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_RESOLVER_H
+#define GRPC_CORE_CLIENT_CONFIG_RESOLVER_H
 
 #include "src/core/client_config/client_config.h"
 #include "src/core/client_config/subchannel.h"
@@ -91,4 +91,4 @@ void grpc_resolver_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
                         grpc_client_config **target_config,
                         grpc_closure *on_complete);
 
-#endif /* GRPC_INTERNAL_CORE_CONFIG_RESOLVER_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_RESOLVER_H */
diff --git a/src/core/client_config/resolver_factory.h b/src/core/client_config/resolver_factory.h
index 4c4df353f7cbcee3f6096a749bcff2c1c172472a..477f8db7f7113d77be6cc64fcb6fd993038c6151 100644
--- a/src/core/client_config/resolver_factory.h
+++ b/src/core/client_config/resolver_factory.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_FACTORY_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_FACTORY_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_RESOLVER_FACTORY_H
+#define GRPC_CORE_CLIENT_CONFIG_RESOLVER_FACTORY_H
 
 #include "src/core/client_config/resolver.h"
 #include "src/core/client_config/subchannel_factory.h"
@@ -79,4 +79,4 @@ grpc_resolver *grpc_resolver_factory_create_resolver(
 char *grpc_resolver_factory_get_default_authority(
     grpc_resolver_factory *factory, grpc_uri *uri);
 
-#endif /* GRPC_INTERNAL_CORE_CONFIG_RESOLVER_FACTORY_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_RESOLVER_FACTORY_H */
diff --git a/src/core/client_config/resolver_registry.h b/src/core/client_config/resolver_registry.h
index 5a7193b7ae258ace3cda801f1699378423f2243c..1e4cebee0baa7053a4a1fc758d632ef4d37c6008 100644
--- a/src/core/client_config/resolver_registry.h
+++ b/src/core/client_config/resolver_registry.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_REGISTRY_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_REGISTRY_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_RESOLVER_REGISTRY_H
+#define GRPC_CORE_CLIENT_CONFIG_RESOLVER_REGISTRY_H
 
 #include "src/core/client_config/resolver_factory.h"
 
@@ -62,4 +62,4 @@ grpc_resolver *grpc_resolver_create(
     representing the default authority to pass from a client. */
 char *grpc_get_default_authority(const char *target);
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_REGISTRY_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_RESOLVER_REGISTRY_H */
diff --git a/src/core/client_config/resolvers/dns_resolver.h b/src/core/client_config/resolvers/dns_resolver.h
index a3ef3161a63f6c6087525faaf4b391bee0877296..b24280b507c2faf4ecaed18378141284d39f241c 100644
--- a/src/core/client_config/resolvers/dns_resolver.h
+++ b/src/core/client_config/resolvers/dns_resolver.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H
+#define GRPC_CORE_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H
 
 #include "src/core/client_config/resolver_factory.h"
 
 /** Create a dns resolver factory */
 grpc_resolver_factory *grpc_dns_resolver_factory_create(void);
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H */
diff --git a/src/core/client_config/resolvers/sockaddr_resolver.h b/src/core/client_config/resolvers/sockaddr_resolver.h
index 1b7a18f9c2ac272950922162272afe37706577ef..f050329431e5ed4b5673ee6e962d5b48e556ad45 100644
--- a/src/core/client_config/resolvers/sockaddr_resolver.h
+++ b/src/core/client_config/resolvers/sockaddr_resolver.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_UNIX_RESOLVER_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_UNIX_RESOLVER_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_RESOLVERS_SOCKADDR_RESOLVER_H
+#define GRPC_CORE_CLIENT_CONFIG_RESOLVERS_SOCKADDR_RESOLVER_H
 
 #include <grpc/support/port_platform.h>
 
@@ -47,4 +47,4 @@ grpc_resolver_factory *grpc_ipv6_resolver_factory_create(void);
 grpc_resolver_factory *grpc_unix_resolver_factory_create(void);
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_UNIX_RESOLVER_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_RESOLVERS_SOCKADDR_RESOLVER_H */
diff --git a/src/core/client_config/resolvers/zookeeper_resolver.h b/src/core/client_config/resolvers/zookeeper_resolver.h
index a6f002dd6d487bc7bb098fa4991cbf86ee744865..04bd3ca875e5937c014e48e20c4da21ee668dda9 100644
--- a/src/core/client_config/resolvers/zookeeper_resolver.h
+++ b/src/core/client_config/resolvers/zookeeper_resolver.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H
+#define GRPC_CORE_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H
 
 #include "src/core/client_config/resolver_factory.h"
 
 /** Create a zookeeper resolver factory */
 grpc_resolver_factory *grpc_zookeeper_resolver_factory_create(void);
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H */
diff --git a/src/core/client_config/subchannel.c b/src/core/client_config/subchannel.c
index ec9e47a6ddb648a647312d55ac2a3e7ca74e2ec2..5dea21566853015b300b22cb07d0d0f01ce101a9 100644
--- a/src/core/client_config/subchannel.c
+++ b/src/core/client_config/subchannel.c
@@ -45,6 +45,7 @@
 #include "src/core/client_config/subchannel_index.h"
 #include "src/core/iomgr/timer.h"
 #include "src/core/profiling/timers.h"
+#include "src/core/support/backoff.h"
 #include "src/core/surface/channel.h"
 #include "src/core/transport/connectivity_state.h"
 
@@ -127,8 +128,8 @@ struct grpc_subchannel {
 
   /** next connect attempt time */
   gpr_timespec next_attempt;
-  /** amount to backoff each failure */
-  gpr_timespec backoff_delta;
+  /** backoff state */
+  gpr_backoff backoff_state;
   /** do we have an active alarm? */
   int have_alarm;
   /** our alarm */
@@ -146,7 +147,6 @@ struct grpc_subchannel_call {
 #define CALLSTACK_TO_SUBCHANNEL_CALL(callstack) \
   (((grpc_subchannel_call *)(callstack)) - 1)
 
-static gpr_timespec compute_connect_deadline(grpc_subchannel *c);
 static void subchannel_connected(grpc_exec_ctx *exec_ctx, void *subchannel,
                                  bool iomgr_success);
 
@@ -337,6 +337,22 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
   grpc_closure_init(&c->connected, subchannel_connected, c);
   grpc_connectivity_state_init(&c->state_tracker, GRPC_CHANNEL_IDLE,
                                "subchannel");
+  gpr_backoff_init(&c->backoff_state,
+                   GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER,
+                   GRPC_SUBCHANNEL_RECONNECT_JITTER,
+                   GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000,
+                   GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
+  if (c->args) {
+    for (size_t i = 0; i < c->args->num_args; i++) {
+      if (0 == strcmp(c->args->args[i].key,
+                      "grpc.testing.fixed_reconnect_backoff")) {
+        GPR_ASSERT(c->args->args[i].type == GRPC_ARG_INTEGER);
+        gpr_backoff_init(&c->backoff_state, 1.0, 0.0,
+                         c->args->args[i].value.integer,
+                         c->args->args[i].value.integer);
+      }
+    }
+  }
   gpr_mu_init(&c->mu);
 
   return grpc_subchannel_index_register(exec_ctx, key, c);
@@ -348,7 +364,7 @@ static void continue_connect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
   args.interested_parties = c->pollset_set;
   args.addr = c->addr;
   args.addr_len = c->addr_len;
-  args.deadline = compute_connect_deadline(c);
+  args.deadline = c->next_attempt;
   args.channel_args = c->args;
   args.initial_connect_string = c->initial_connect_string;
 
@@ -359,10 +375,8 @@ static void continue_connect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
 }
 
 static void start_connect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
-  c->backoff_delta = gpr_time_from_seconds(
-      GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS, GPR_TIMESPAN);
   c->next_attempt =
-      gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), c->backoff_delta);
+      gpr_backoff_begin(&c->backoff_state, gpr_now(GPR_CLOCK_MONOTONIC));
   continue_connect(exec_ctx, c);
 }
 
@@ -577,50 +591,6 @@ static void publish_transport_locked(grpc_exec_ctx *exec_ctx,
   gpr_free((void *)filters);
 }
 
-/* Generate a random number between 0 and 1. */
-static double generate_uniform_random_number(grpc_subchannel *c) {
-  c->random = (1103515245 * c->random + 12345) % ((uint32_t)1 << 31);
-  return c->random / (double)((uint32_t)1 << 31);
-}
-
-/* Update backoff_delta and next_attempt in subchannel */
-static void update_reconnect_parameters(grpc_subchannel *c) {
-  size_t i;
-  int32_t backoff_delta_millis, jitter;
-  int32_t max_backoff_millis =
-      GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS * 1000;
-  double jitter_range;
-
-  if (c->args) {
-    for (i = 0; i < c->args->num_args; i++) {
-      if (0 == strcmp(c->args->args[i].key,
-                      "grpc.testing.fixed_reconnect_backoff")) {
-        GPR_ASSERT(c->args->args[i].type == GRPC_ARG_INTEGER);
-        c->next_attempt = gpr_time_add(
-            gpr_now(GPR_CLOCK_MONOTONIC),
-            gpr_time_from_millis(c->args->args[i].value.integer, GPR_TIMESPAN));
-        return;
-      }
-    }
-  }
-
-  backoff_delta_millis =
-      (int32_t)(gpr_time_to_millis(c->backoff_delta) *
-                GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER);
-  if (backoff_delta_millis > max_backoff_millis) {
-    backoff_delta_millis = max_backoff_millis;
-  }
-  c->backoff_delta = gpr_time_from_millis(backoff_delta_millis, GPR_TIMESPAN);
-  c->next_attempt =
-      gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), c->backoff_delta);
-
-  jitter_range = GRPC_SUBCHANNEL_RECONNECT_JITTER * backoff_delta_millis;
-  jitter =
-      (int32_t)((2 * generate_uniform_random_number(c) - 1) * jitter_range);
-  c->next_attempt =
-      gpr_time_add(c->next_attempt, gpr_time_from_millis(jitter, GPR_TIMESPAN));
-}
-
 static void on_alarm(grpc_exec_ctx *exec_ctx, void *arg, bool iomgr_success) {
   grpc_subchannel *c = arg;
   gpr_mu_lock(&c->mu);
@@ -629,7 +599,8 @@ static void on_alarm(grpc_exec_ctx *exec_ctx, void *arg, bool iomgr_success) {
     iomgr_success = 0;
   }
   if (iomgr_success) {
-    update_reconnect_parameters(c);
+    c->next_attempt =
+        gpr_backoff_step(&c->backoff_state, gpr_now(GPR_CLOCK_MONOTONIC));
     continue_connect(exec_ctx, c);
     gpr_mu_unlock(&c->mu);
   } else {
@@ -661,17 +632,6 @@ static void subchannel_connected(grpc_exec_ctx *exec_ctx, void *arg,
   GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting");
 }
 
-static gpr_timespec compute_connect_deadline(grpc_subchannel *c) {
-  gpr_timespec current_deadline =
-      gpr_time_add(c->next_attempt, c->backoff_delta);
-  gpr_timespec min_deadline = gpr_time_add(
-      gpr_now(GPR_CLOCK_MONOTONIC),
-      gpr_time_from_seconds(GRPC_SUBCHANNEL_MIN_CONNECT_TIMEOUT_SECONDS,
-                            GPR_TIMESPAN));
-  return gpr_time_cmp(current_deadline, min_deadline) > 0 ? current_deadline
-                                                          : min_deadline;
-}
-
 /*
  * grpc_subchannel_call implementation
  */
diff --git a/src/core/client_config/subchannel.h b/src/core/client_config/subchannel.h
index 313e63c75c83ac1a47bd05ace90cb8a00c4eb5be..ef9f2f1d1e06d2d4cc4ad35a208cdbd10a0f11eb 100644
--- a/src/core/client_config/subchannel.h
+++ b/src/core/client_config/subchannel.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_SUBCHANNEL_H
+#define GRPC_CORE_CLIENT_CONFIG_SUBCHANNEL_H
 
 #include "src/core/channel/channel_stack.h"
 #include "src/core/client_config/connector.h"
@@ -171,4 +171,4 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
                                         grpc_connector *connector,
                                         grpc_subchannel_args *args);
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_SUBCHANNEL_H */
diff --git a/src/core/client_config/subchannel_factory.h b/src/core/client_config/subchannel_factory.h
index c6d8cc90bed7f262577b2f1fe937ccd3d62ee232..c638f377a6049dde65bcac59d657aa5a62000d88 100644
--- a/src/core/client_config/subchannel_factory.h
+++ b/src/core/client_config/subchannel_factory.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
+#define GRPC_CORE_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
 
 #include "src/core/channel/channel_stack.h"
 #include "src/core/client_config/subchannel.h"
@@ -63,4 +63,4 @@ grpc_subchannel *grpc_subchannel_factory_create_subchannel(
     grpc_exec_ctx *exec_ctx, grpc_subchannel_factory *factory,
     grpc_subchannel_args *args);
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H */
diff --git a/src/core/client_config/subchannel_index.h b/src/core/client_config/subchannel_index.h
index 095ef178194bc397fc934b6642dd9bc3b1ced054..3cd5d12349295965f664b65402804b23f1ddf1dc 100644
--- a/src/core/client_config/subchannel_index.h
+++ b/src/core/client_config/subchannel_index.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
+#define GRPC_CORE_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
 
 #include "src/core/client_config/connector.h"
 #include "src/core/client_config/subchannel.h"
@@ -74,4 +74,4 @@ void grpc_subchannel_index_init(void);
 /** Shutdown the subchannel index (global) */
 void grpc_subchannel_index_shutdown(void);
 
-#endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_INDEX_H */
+#endif /* GRPC_CORE_CLIENT_CONFIG_SUBCHANNEL_INDEX_H */
diff --git a/src/core/client_config/uri_parser.h b/src/core/client_config/uri_parser.h
index b8daa13bd4f66a0f39ccc210fab025851e3f026c..af013d8cac66ad45316f0eabf858bf04aee86136 100644
--- a/src/core/client_config/uri_parser.h
+++ b/src/core/client_config/uri_parser.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_URI_PARSER_H
-#define GRPC_INTERNAL_CORE_CLIENT_CONFIG_URI_PARSER_H
+#ifndef GRPC_CORE_CLIENT_CONFIG_URI_PARSER_H
+#define GRPC_CORE_CLIENT_CONFIG_URI_PARSER_H
 
 typedef struct {
   char *scheme;
@@ -48,4 +48,4 @@ grpc_uri *grpc_uri_parse(const char *uri_text, int suppress_errors);
 /** destroy a uri */
 void grpc_uri_destroy(grpc_uri *uri);
 
-#endif
+#endif /* GRPC_CORE_CLIENT_CONFIG_URI_PARSER_H */
diff --git a/src/core/compression/algorithm_metadata.h b/src/core/compression/algorithm_metadata.h
index 882633c3074ebd8dcd5ac5393b2097990aeeab30..34abf1dba29d2f5b5429d954ae4b78c644d041c8 100644
--- a/src/core/compression/algorithm_metadata.h
+++ b/src/core/compression/algorithm_metadata.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_COMPRESSION_ALGORITHM_METADATA_H
-#define GRPC_INTERNAL_CORE_COMPRESSION_ALGORITHM_METADATA_H
+#ifndef GRPC_CORE_COMPRESSION_ALGORITHM_METADATA_H
+#define GRPC_CORE_COMPRESSION_ALGORITHM_METADATA_H
 
 #include <grpc/compression.h>
 #include "src/core/transport/metadata.h"
@@ -50,4 +50,4 @@ grpc_mdelem *grpc_compression_encoding_mdelem(
 grpc_compression_algorithm grpc_compression_algorithm_from_mdstr(
     grpc_mdstr *str);
 
-#endif /* GRPC_INTERNAL_CORE_COMPRESSION_ALGORITHM_METADATA_H */
+#endif /* GRPC_CORE_COMPRESSION_ALGORITHM_METADATA_H */
diff --git a/src/core/compression/message_compress.h b/src/core/compression/message_compress.h
index 14652004b860074bc3011057d57ea48076a0213d..20b78c063b34af0c8470e6745772ba28ed2b204a 100644
--- a/src/core/compression/message_compress.h
+++ b/src/core/compression/message_compress.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_COMPRESSION_MESSAGE_COMPRESS_H
-#define GRPC_INTERNAL_CORE_COMPRESSION_MESSAGE_COMPRESS_H
+#ifndef GRPC_CORE_COMPRESSION_MESSAGE_COMPRESS_H
+#define GRPC_CORE_COMPRESSION_MESSAGE_COMPRESS_H
 
 #include <grpc/compression.h>
 #include <grpc/support/slice_buffer.h>
@@ -49,4 +49,4 @@ int grpc_msg_compress(grpc_compression_algorithm algorithm,
 int grpc_msg_decompress(grpc_compression_algorithm algorithm,
                         gpr_slice_buffer* input, gpr_slice_buffer* output);
 
-#endif /* GRPC_INTERNAL_CORE_COMPRESSION_MESSAGE_COMPRESS_H */
+#endif /* GRPC_CORE_COMPRESSION_MESSAGE_COMPRESS_H */
diff --git a/src/core/debug/trace.h b/src/core/debug/trace.h
index dc5875976e2595b84ceab5823055872852ead19f..91ec14052e96404f2186cc8cc72bf8eca4eba247 100644
--- a/src/core/debug/trace.h
+++ b/src/core/debug/trace.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_DEBUG_TRACE_H
-#define GRPC_INTERNAL_CORE_DEBUG_TRACE_H
+#ifndef GRPC_CORE_DEBUG_TRACE_H
+#define GRPC_CORE_DEBUG_TRACE_H
 
 #include <grpc/support/port_platform.h>
 
@@ -40,4 +40,4 @@ void grpc_register_tracer(const char *name, int *flag);
 void grpc_tracer_init(const char *env_var_name);
 void grpc_tracer_shutdown(void);
 
-#endif /* GRPC_INTERNAL_CORE_DEBUG_TRACE_H */
+#endif /* GRPC_CORE_DEBUG_TRACE_H */
diff --git a/src/core/httpcli/format_request.h b/src/core/httpcli/format_request.h
index c8dc8f7d4ee06f0553d80ae24df35c41720f92bd..eb47cc90ca5eb7e03358c6a5c03a2ffc0a9dfc2e 100644
--- a/src/core/httpcli/format_request.h
+++ b/src/core/httpcli/format_request.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_HTTPCLI_FORMAT_REQUEST_H
-#define GRPC_INTERNAL_CORE_HTTPCLI_FORMAT_REQUEST_H
+#ifndef GRPC_CORE_HTTPCLI_FORMAT_REQUEST_H
+#define GRPC_CORE_HTTPCLI_FORMAT_REQUEST_H
 
 #include "src/core/httpcli/httpcli.h"
 #include <grpc/support/slice.h>
@@ -42,4 +42,4 @@ gpr_slice grpc_httpcli_format_post_request(const grpc_httpcli_request *request,
                                            const char *body_bytes,
                                            size_t body_size);
 
-#endif /* GRPC_INTERNAL_CORE_HTTPCLI_FORMAT_REQUEST_H */
+#endif /* GRPC_CORE_HTTPCLI_FORMAT_REQUEST_H */
diff --git a/src/core/httpcli/httpcli.h b/src/core/httpcli/httpcli.h
index c9cd987c794f505dd8258a3af74a00dbad2e10aa..1fe5782657a4ca59ceaf46260e2392479b632fcf 100644
--- a/src/core/httpcli/httpcli.h
+++ b/src/core/httpcli/httpcli.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_HTTPCLI_HTTPCLI_H
-#define GRPC_INTERNAL_CORE_HTTPCLI_HTTPCLI_H
+#ifndef GRPC_CORE_HTTPCLI_HTTPCLI_H
+#define GRPC_CORE_HTTPCLI_HTTPCLI_H
 
 #include <stddef.h>
 
@@ -160,4 +160,4 @@ typedef int (*grpc_httpcli_post_override)(
 void grpc_httpcli_set_override(grpc_httpcli_get_override get,
                                grpc_httpcli_post_override post);
 
-#endif /* GRPC_INTERNAL_CORE_HTTPCLI_HTTPCLI_H */
+#endif /* GRPC_CORE_HTTPCLI_HTTPCLI_H */
diff --git a/src/core/httpcli/parser.h b/src/core/httpcli/parser.h
index cd0383637fff9e461741402e215036d7ac037826..cd4a737245c6b7eb1f2b1f78b9a6cef99e9d7a06 100644
--- a/src/core/httpcli/parser.h
+++ b/src/core/httpcli/parser.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_HTTPCLI_PARSER_H
-#define GRPC_INTERNAL_CORE_HTTPCLI_PARSER_H
+#ifndef GRPC_CORE_HTTPCLI_PARSER_H
+#define GRPC_CORE_HTTPCLI_PARSER_H
 
 #include "src/core/httpcli/httpcli.h"
 #include <grpc/support/port_platform.h>
@@ -61,4 +61,4 @@ void grpc_httpcli_parser_destroy(grpc_httpcli_parser* parser);
 int grpc_httpcli_parser_parse(grpc_httpcli_parser* parser, gpr_slice slice);
 int grpc_httpcli_parser_eof(grpc_httpcli_parser* parser);
 
-#endif /* GRPC_INTERNAL_CORE_HTTPCLI_PARSER_H */
+#endif /* GRPC_CORE_HTTPCLI_PARSER_H */
diff --git a/src/core/iomgr/closure.h b/src/core/iomgr/closure.h
index ea96c19c71b235c3980872eb2c54bdbac238b8e2..d5e1f455b9ad7a6d4a1988d53c4c2baca3e21e29 100644
--- a/src/core/iomgr/closure.h
+++ b/src/core/iomgr/closure.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_CLOSURE_H
-#define GRPC_INTERNAL_CORE_IOMGR_CLOSURE_H
+#ifndef GRPC_CORE_IOMGR_CLOSURE_H
+#define GRPC_CORE_IOMGR_CLOSURE_H
 
 #include <grpc/support/port_platform.h>
 #include <stdbool.h>
@@ -95,4 +95,4 @@ bool grpc_closure_list_empty(grpc_closure_list list);
 /** return the next pointer for a queued closure list */
 grpc_closure *grpc_closure_next(grpc_closure *closure);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_CLOSURE_H */
+#endif /* GRPC_CORE_IOMGR_CLOSURE_H */
diff --git a/src/core/iomgr/endpoint.h b/src/core/iomgr/endpoint.h
index cbdc947abbfdd062982ba82f68b56337fe577d14..788f3ac5bcd1553456426040bcd88c14a2434fe4 100644
--- a/src/core/iomgr/endpoint.h
+++ b/src/core/iomgr/endpoint.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_ENDPOINT_H
-#define GRPC_INTERNAL_CORE_IOMGR_ENDPOINT_H
+#ifndef GRPC_CORE_IOMGR_ENDPOINT_H
+#define GRPC_CORE_IOMGR_ENDPOINT_H
 
 #include "src/core/iomgr/pollset.h"
 #include "src/core/iomgr/pollset_set.h"
@@ -99,4 +99,4 @@ struct grpc_endpoint {
   const grpc_endpoint_vtable *vtable;
 };
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_ENDPOINT_H */
+#endif /* GRPC_CORE_IOMGR_ENDPOINT_H */
diff --git a/src/core/iomgr/endpoint_pair.h b/src/core/iomgr/endpoint_pair.h
index 095ec5fcc9fc3f75b3b7b42821c69541e47662ff..59015d8ffbe358d71a30ea2f35b1b80af0f1a292 100644
--- a/src/core/iomgr/endpoint_pair.h
+++ b/src/core/iomgr/endpoint_pair.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_ENDPOINT_PAIR_H
-#define GRPC_INTERNAL_CORE_IOMGR_ENDPOINT_PAIR_H
+#ifndef GRPC_CORE_IOMGR_ENDPOINT_PAIR_H
+#define GRPC_CORE_IOMGR_ENDPOINT_PAIR_H
 
 #include "src/core/iomgr/endpoint.h"
 
@@ -44,4 +44,4 @@ typedef struct {
 grpc_endpoint_pair grpc_iomgr_create_endpoint_pair(const char *name,
                                                    size_t read_slice_size);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_ENDPOINT_PAIR_H */
+#endif /* GRPC_CORE_IOMGR_ENDPOINT_PAIR_H */
diff --git a/src/core/iomgr/exec_ctx.h b/src/core/iomgr/exec_ctx.h
index 1b627a5dcf8c50ee494f04938e220880e8692982..07b54a0ab81466e1d64ea578548f9b74d9d421a2 100644
--- a/src/core/iomgr/exec_ctx.h
+++ b/src/core/iomgr/exec_ctx.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_EXEC_CTX_H
-#define GRPC_INTERNAL_CORE_IOMGR_EXEC_CTX_H
+#ifndef GRPC_CORE_IOMGR_EXEC_CTX_H
+#define GRPC_CORE_IOMGR_EXEC_CTX_H
 
 #include "src/core/iomgr/closure.h"
 
@@ -95,4 +95,4 @@ void grpc_exec_ctx_enqueue_list(grpc_exec_ctx *exec_ctx,
 void grpc_exec_ctx_global_init(void);
 void grpc_exec_ctx_global_shutdown(void);
 
-#endif
+#endif /* GRPC_CORE_IOMGR_EXEC_CTX_H */
diff --git a/src/core/iomgr/executor.h b/src/core/iomgr/executor.h
index aac057ddf5fb9699826261c2ad951a5c9c0b7861..f66b3560e372f23cf17aeb4b9b7412fdc2b94a6c 100644
--- a/src/core/iomgr/executor.h
+++ b/src/core/iomgr/executor.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_EXECUTOR_H
-#define GRPC_INTERNAL_CORE_IOMGR_EXECUTOR_H
+#ifndef GRPC_CORE_IOMGR_EXECUTOR_H
+#define GRPC_CORE_IOMGR_EXECUTOR_H
 
 #include "src/core/iomgr/closure.h"
 
@@ -50,4 +50,4 @@ void grpc_executor_enqueue(grpc_closure *closure, bool success);
 /** Shutdown the executor, running all pending work as part of the call */
 void grpc_executor_shutdown();
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_EXECUTOR_H */
+#endif /* GRPC_CORE_IOMGR_EXECUTOR_H */
diff --git a/src/core/iomgr/fd_posix.h b/src/core/iomgr/fd_posix.h
index 17e7de88ffaa64b476a6e24491e75cda276ce592..a5c8ff1d9acc78d922abcb64c789c3c120ab3eec 100644
--- a/src/core/iomgr/fd_posix.h
+++ b/src/core/iomgr/fd_posix.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_FD_POSIX_H
-#define GRPC_INTERNAL_CORE_IOMGR_FD_POSIX_H
+#ifndef GRPC_CORE_IOMGR_FD_POSIX_H
+#define GRPC_CORE_IOMGR_FD_POSIX_H
 
 #include "src/core/iomgr/iomgr_internal.h"
 #include "src/core/iomgr/pollset.h"
@@ -189,4 +189,4 @@ void grpc_fd_unref(grpc_fd *fd);
 void grpc_fd_global_init(void);
 void grpc_fd_global_shutdown(void);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_FD_POSIX_H */
+#endif /* GRPC_CORE_IOMGR_FD_POSIX_H */
diff --git a/src/core/iomgr/iocp_windows.h b/src/core/iomgr/iocp_windows.h
index 8b2b1aeb5c2a950c0e440a19f19040257cc78a3c..570b8925aa369e296ed5e2e0676406cdf862f5e8 100644
--- a/src/core/iomgr/iocp_windows.h
+++ b/src/core/iomgr/iocp_windows.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_IOCP_WINDOWS_H
-#define GRPC_INTERNAL_CORE_IOMGR_IOCP_WINDOWS_H
+#ifndef GRPC_CORE_IOMGR_IOCP_WINDOWS_H
+#define GRPC_CORE_IOMGR_IOCP_WINDOWS_H
 
 #include <grpc/support/sync.h>
 
@@ -60,4 +60,4 @@ void grpc_socket_notify_on_read(grpc_exec_ctx *exec_ctx,
                                 grpc_winsocket *winsocket,
                                 grpc_closure *closure);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_IOCP_WINDOWS_H */
+#endif /* GRPC_CORE_IOMGR_IOCP_WINDOWS_H */
diff --git a/src/core/iomgr/iomgr.h b/src/core/iomgr/iomgr.h
index c9ea84c6050b97bbb8eb60a6011ded7280dcbe65..e1237a4533e36d5400acdc49b3ab8f29232a71d0 100644
--- a/src/core/iomgr/iomgr.h
+++ b/src/core/iomgr/iomgr.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_IOMGR_H
-#define GRPC_INTERNAL_CORE_IOMGR_IOMGR_H
+#ifndef GRPC_CORE_IOMGR_IOMGR_H
+#define GRPC_CORE_IOMGR_IOMGR_H
 
 /** Initializes the iomgr. */
 void grpc_iomgr_init(void);
@@ -40,4 +40,4 @@ void grpc_iomgr_init(void);
 /** Signals the intention to shutdown the iomgr. */
 void grpc_iomgr_shutdown(void);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_IOMGR_H */
+#endif /* GRPC_CORE_IOMGR_IOMGR_H */
diff --git a/src/core/iomgr/iomgr_internal.h b/src/core/iomgr/iomgr_internal.h
index ac2c46ebe6230df3242f4a8a3cb04ba7b3cf7dbf..d06b068b1c13c96382060a76d0077916a2dec91e 100644
--- a/src/core/iomgr/iomgr_internal.h
+++ b/src/core/iomgr/iomgr_internal.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_IOMGR_INTERNAL_H
-#define GRPC_INTERNAL_CORE_IOMGR_IOMGR_INTERNAL_H
+#ifndef GRPC_CORE_IOMGR_IOMGR_INTERNAL_H
+#define GRPC_CORE_IOMGR_IOMGR_INTERNAL_H
 
 #include <stdbool.h>
 
@@ -59,4 +59,4 @@ void grpc_iomgr_platform_shutdown(void);
 
 bool grpc_iomgr_abort_on_leaks(void);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_IOMGR_INTERNAL_H */
+#endif /* GRPC_CORE_IOMGR_IOMGR_INTERNAL_H */
diff --git a/src/core/iomgr/iomgr_posix.h b/src/core/iomgr/iomgr_posix.h
index 068a5c6d7cf17a43f50595e25094e91f2bcd85ee..698fb6aee706d1407948e8962d4160ece0fc1e94 100644
--- a/src/core/iomgr/iomgr_posix.h
+++ b/src/core/iomgr/iomgr_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,9 +31,9 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_IOMGR_POSIX_H
-#define GRPC_INTERNAL_CORE_IOMGR_IOMGR_POSIX_H
+#ifndef GRPC_CORE_IOMGR_IOMGR_POSIX_H
+#define GRPC_CORE_IOMGR_IOMGR_POSIX_H
 
 #include "src/core/iomgr/iomgr_internal.h"
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_IOMGR_POSIX_H */
+#endif /* GRPC_CORE_IOMGR_IOMGR_POSIX_H */
diff --git a/src/core/iomgr/pollset.h b/src/core/iomgr/pollset.h
index ee1debfb719bc098ed2074b9825ca554108203cb..9500b1a73a906be876ef6eceaa75fff1fabf7842 100644
--- a/src/core/iomgr/pollset.h
+++ b/src/core/iomgr/pollset.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_POLLSET_H
-#define GRPC_INTERNAL_CORE_IOMGR_POLLSET_H
+#ifndef GRPC_CORE_IOMGR_POLLSET_H
+#define GRPC_CORE_IOMGR_POLLSET_H
 
 #include <grpc/support/port_platform.h>
 #include <grpc/support/sync.h>
@@ -91,4 +91,4 @@ void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
 void grpc_pollset_kick(grpc_pollset *pollset,
                        grpc_pollset_worker *specific_worker);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_POLLSET_H */
+#endif /* GRPC_CORE_IOMGR_POLLSET_H */
diff --git a/src/core/iomgr/pollset_posix.h b/src/core/iomgr/pollset_posix.h
index bbedb66b0076dbbeaf8a94dab07a5de90da5e931..e0cfc44395072e1dee32f05a4e7a5309532189b4 100644
--- a/src/core/iomgr/pollset_posix.h
+++ b/src/core/iomgr/pollset_posix.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_POLLSET_POSIX_H
-#define GRPC_INTERNAL_CORE_IOMGR_POLLSET_POSIX_H
+#ifndef GRPC_CORE_IOMGR_POLLSET_POSIX_H
+#define GRPC_CORE_IOMGR_POLLSET_POSIX_H
 
 #include <poll.h>
 
@@ -150,4 +150,4 @@ typedef int (*grpc_poll_function_type)(struct pollfd *, nfds_t, int);
 extern grpc_poll_function_type grpc_poll_function;
 extern grpc_wakeup_fd grpc_global_wakeup_fd;
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_POLLSET_POSIX_H */
+#endif /* GRPC_CORE_IOMGR_POLLSET_POSIX_H */
diff --git a/src/core/iomgr/pollset_set.h b/src/core/iomgr/pollset_set.h
index dddcd8313f220a63ba0c934b69f2fd53b1026e33..204c6259337bce86ad602814facdea7bcc6550a7 100644
--- a/src/core/iomgr/pollset_set.h
+++ b/src/core/iomgr/pollset_set.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_POLLSET_SET_H
-#define GRPC_INTERNAL_CORE_IOMGR_POLLSET_SET_H
+#ifndef GRPC_CORE_IOMGR_POLLSET_SET_H
+#define GRPC_CORE_IOMGR_POLLSET_SET_H
 
 #include "src/core/iomgr/pollset.h"
 
@@ -58,4 +58,4 @@ void grpc_pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx,
                                       grpc_pollset_set *bag,
                                       grpc_pollset_set *item);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_POLLSET_H */
+#endif /* GRPC_CORE_IOMGR_POLLSET_SET_H */
diff --git a/src/core/iomgr/pollset_set_posix.h b/src/core/iomgr/pollset_set_posix.h
index 7d1aaf41817fe3845c1697f44cd1025492992691..80f487718e42310e7d34eada507a4464370959c7 100644
--- a/src/core/iomgr/pollset_set_posix.h
+++ b/src/core/iomgr/pollset_set_posix.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_POLLSET_SET_POSIX_H
-#define GRPC_INTERNAL_CORE_IOMGR_POLLSET_SET_POSIX_H
+#ifndef GRPC_CORE_IOMGR_POLLSET_SET_POSIX_H
+#define GRPC_CORE_IOMGR_POLLSET_SET_POSIX_H
 
 #include "src/core/iomgr/fd_posix.h"
 #include "src/core/iomgr/pollset_set.h"
@@ -42,4 +42,4 @@ void grpc_pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
 void grpc_pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
                              grpc_pollset_set *pollset_set, grpc_fd *fd);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_POLLSET_WINDOWS_H */
+#endif /* GRPC_CORE_IOMGR_POLLSET_SET_POSIX_H */
diff --git a/src/core/iomgr/pollset_set_windows.h b/src/core/iomgr/pollset_set_windows.h
index 9661cd2c3987223efbbe44f0f5a0ff2abc4425c9..0f040fef82242765c4cee06c66f2c9e1fc6dcda8 100644
--- a/src/core/iomgr/pollset_set_windows.h
+++ b/src/core/iomgr/pollset_set_windows.h
@@ -31,9 +31,9 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_POLLSET_SET_WINDOWS_H
-#define GRPC_INTERNAL_CORE_IOMGR_POLLSET_SET_WINDOWS_H
+#ifndef GRPC_CORE_IOMGR_POLLSET_SET_WINDOWS_H
+#define GRPC_CORE_IOMGR_POLLSET_SET_WINDOWS_H
 
 #include "src/core/iomgr/pollset_set.h"
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_POLLSET_WINDOWS_H */
+#endif /* GRPC_CORE_IOMGR_POLLSET_SET_WINDOWS_H */
diff --git a/src/core/iomgr/pollset_windows.h b/src/core/iomgr/pollset_windows.h
index dc0b7a4104bd8ada3c4d0301044465d1e3e204fc..f1d158592228aedded006e9615bc8ab220624f94 100644
--- a/src/core/iomgr/pollset_windows.h
+++ b/src/core/iomgr/pollset_windows.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_POLLSET_WINDOWS_H
-#define GRPC_INTERNAL_CORE_IOMGR_POLLSET_WINDOWS_H
+#ifndef GRPC_CORE_IOMGR_POLLSET_WINDOWS_H
+#define GRPC_CORE_IOMGR_POLLSET_WINDOWS_H
 
 #include <grpc/support/sync.h>
 
@@ -72,4 +72,4 @@ struct grpc_pollset {
   grpc_closure *on_shutdown;
 };
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_POLLSET_WINDOWS_H */
+#endif /* GRPC_CORE_IOMGR_POLLSET_WINDOWS_H */
diff --git a/src/core/iomgr/resolve_address.h b/src/core/iomgr/resolve_address.h
index b059630457656bc5676335e7621c2591dcc8e8fc..aa0d7d194b83bdee7f8062bb3a6815cd6161defe 100644
--- a/src/core/iomgr/resolve_address.h
+++ b/src/core/iomgr/resolve_address.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_RESOLVE_ADDRESS_H
-#define GRPC_INTERNAL_CORE_IOMGR_RESOLVE_ADDRESS_H
+#ifndef GRPC_CORE_IOMGR_RESOLVE_ADDRESS_H
+#define GRPC_CORE_IOMGR_RESOLVE_ADDRESS_H
 
 #include <stddef.h>
 #include "src/core/iomgr/exec_ctx.h"
@@ -69,4 +69,4 @@ void grpc_resolved_addresses_destroy(grpc_resolved_addresses *addresses);
 extern grpc_resolved_addresses *(*grpc_blocking_resolve_address)(
     const char *name, const char *default_port);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_RESOLVE_ADDRESS_H */
+#endif /* GRPC_CORE_IOMGR_RESOLVE_ADDRESS_H */
diff --git a/src/core/iomgr/sockaddr.h b/src/core/iomgr/sockaddr.h
index e41e1ec6b48ed8edb4faa62f957ccaafc120e956..68241bdd55dee4510a83cf60d71541748b3f7b70 100644
--- a/src/core/iomgr/sockaddr.h
+++ b/src/core/iomgr/sockaddr.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_H
-#define GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_H
+#ifndef GRPC_CORE_IOMGR_SOCKADDR_H
+#define GRPC_CORE_IOMGR_SOCKADDR_H
 
 #include <grpc/support/port_platform.h>
 
@@ -44,4 +44,4 @@
 #include "src/core/iomgr/sockaddr_posix.h"
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_H */
+#endif /* GRPC_CORE_IOMGR_SOCKADDR_H */
diff --git a/src/core/iomgr/sockaddr_posix.h b/src/core/iomgr/sockaddr_posix.h
index 388abb3306691526ecd732adad0bafaa0a9c7884..e4425ed7352219d5130ebd2608bbd3ed20b71ebd 100644
--- a/src/core/iomgr/sockaddr_posix.h
+++ b/src/core/iomgr/sockaddr_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_POSIX_H
-#define GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_POSIX_H
+#ifndef GRPC_CORE_IOMGR_SOCKADDR_POSIX_H
+#define GRPC_CORE_IOMGR_SOCKADDR_POSIX_H
 
 #include <arpa/inet.h>
 #include <sys/socket.h>
@@ -41,4 +41,4 @@
 #include <netdb.h>
 #include <unistd.h>
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_POSIX_H */
+#endif /* GRPC_CORE_IOMGR_SOCKADDR_POSIX_H */
diff --git a/src/core/iomgr/sockaddr_utils.h b/src/core/iomgr/sockaddr_utils.h
index 6f7a279900dff0af65508caface301a898cef550..43dc7a45eccfb7b655d644e3af68bb9b73345e03 100644
--- a/src/core/iomgr/sockaddr_utils.h
+++ b/src/core/iomgr/sockaddr_utils.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_UTILS_H
-#define GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_UTILS_H
+#ifndef GRPC_CORE_IOMGR_SOCKADDR_UTILS_H
+#define GRPC_CORE_IOMGR_SOCKADDR_UTILS_H
 
 #include "src/core/iomgr/sockaddr.h"
 
@@ -86,4 +86,4 @@ int grpc_sockaddr_to_string(char **out, const struct sockaddr *addr,
 
 char *grpc_sockaddr_to_uri(const struct sockaddr *addr);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_UTILS_H */
+#endif /* GRPC_CORE_IOMGR_SOCKADDR_UTILS_H */
diff --git a/src/core/iomgr/sockaddr_win32.h b/src/core/iomgr/sockaddr_win32.h
index 8e3946a7d847cec022d21882a1d5129406f49bef..7acb8f7f57fe41abb3be9be9ae3623c947de9f4e 100644
--- a/src/core/iomgr/sockaddr_win32.h
+++ b/src/core/iomgr/sockaddr_win32.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_WIN32_H
-#define GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_WIN32_H
+#ifndef GRPC_CORE_IOMGR_SOCKADDR_WIN32_H
+#define GRPC_CORE_IOMGR_SOCKADDR_WIN32_H
 
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #include <mswsock.h>
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_SOCKADDR_WIN32_H */
+#endif /* GRPC_CORE_IOMGR_SOCKADDR_WIN32_H */
diff --git a/src/core/iomgr/socket_utils_posix.h b/src/core/iomgr/socket_utils_posix.h
index d330d1986ebd546723922b3a81d681fe0f7e27aa..b01e28b6f2f35360110df640cf907daee2249986 100644
--- a/src/core/iomgr/socket_utils_posix.h
+++ b/src/core/iomgr/socket_utils_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_SOCKET_UTILS_POSIX_H
-#define GRPC_INTERNAL_CORE_IOMGR_SOCKET_UTILS_POSIX_H
+#ifndef GRPC_CORE_IOMGR_SOCKET_UTILS_POSIX_H
+#define GRPC_CORE_IOMGR_SOCKET_UTILS_POSIX_H
 
 #include <unistd.h>
 #include <sys/socket.h>
@@ -110,4 +110,4 @@ extern int grpc_forbid_dualstack_sockets_for_testing;
 int grpc_create_dualstack_socket(const struct sockaddr *addr, int type,
                                  int protocol, grpc_dualstack_mode *dsmode);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_SOCKET_UTILS_POSIX_H */
+#endif /* GRPC_CORE_IOMGR_SOCKET_UTILS_POSIX_H */
diff --git a/src/core/iomgr/socket_windows.h b/src/core/iomgr/socket_windows.h
index dfbfabe1f934cd8bedf5498d805a91028b59501f..8e50e7a95322c988f85ce246600b064ceafbc6a7 100644
--- a/src/core/iomgr/socket_windows.h
+++ b/src/core/iomgr/socket_windows.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_SOCKET_WINDOWS_H
-#define GRPC_INTERNAL_CORE_IOMGR_SOCKET_WINDOWS_H
+#ifndef GRPC_CORE_IOMGR_SOCKET_WINDOWS_H
+#define GRPC_CORE_IOMGR_SOCKET_WINDOWS_H
 
 #include <grpc/support/port_platform.h>
 #include <winsock2.h>
@@ -108,4 +108,4 @@ void grpc_winsocket_shutdown(grpc_winsocket *socket);
 /* Destroy a socket. Should only be called if there's no pending operation. */
 void grpc_winsocket_destroy(grpc_winsocket *socket);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_SOCKET_WINDOWS_H */
+#endif /* GRPC_CORE_IOMGR_SOCKET_WINDOWS_H */
diff --git a/src/core/iomgr/tcp_client.h b/src/core/iomgr/tcp_client.h
index 5e18e71ca2fde8f67c93fec4bb6af96788722e6c..2e29833b7067cbd253bdf31eea45a3d66c1acf24 100644
--- a/src/core/iomgr/tcp_client.h
+++ b/src/core/iomgr/tcp_client.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_TCP_CLIENT_H
-#define GRPC_INTERNAL_CORE_IOMGR_TCP_CLIENT_H
+#ifndef GRPC_CORE_IOMGR_TCP_CLIENT_H
+#define GRPC_CORE_IOMGR_TCP_CLIENT_H
 
 #include "src/core/iomgr/endpoint.h"
 #include "src/core/iomgr/pollset_set.h"
@@ -50,4 +50,4 @@ void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *on_connect,
                              const struct sockaddr *addr, size_t addr_len,
                              gpr_timespec deadline);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_TCP_CLIENT_H */
+#endif /* GRPC_CORE_IOMGR_TCP_CLIENT_H */
diff --git a/src/core/iomgr/tcp_posix.h b/src/core/iomgr/tcp_posix.h
index 2a40cdd38590b20f75464b4e3822949994ffa75e..d846ec570f05b161cf2767ac3d1803e5508a6b06 100644
--- a/src/core/iomgr/tcp_posix.h
+++ b/src/core/iomgr/tcp_posix.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_TCP_POSIX_H
-#define GRPC_INTERNAL_CORE_IOMGR_TCP_POSIX_H
+#ifndef GRPC_CORE_IOMGR_TCP_POSIX_H
+#define GRPC_CORE_IOMGR_TCP_POSIX_H
 /*
    Low level TCP "bottom half" implementation, for use by transports built on
    top of a TCP connection.
@@ -68,4 +68,4 @@ int grpc_tcp_fd(grpc_endpoint *ep);
 void grpc_tcp_destroy_and_release_fd(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
                                      int *fd, grpc_closure *done);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_TCP_POSIX_H */
+#endif /* GRPC_CORE_IOMGR_TCP_POSIX_H */
diff --git a/src/core/iomgr/tcp_server.h b/src/core/iomgr/tcp_server.h
index a39dd3bafce4a59cd2179a686b9e83510111a1b7..93247e9e4e3c4000014b01f73478d5a4c7a102ed 100644
--- a/src/core/iomgr/tcp_server.h
+++ b/src/core/iomgr/tcp_server.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_TCP_SERVER_H
-#define GRPC_INTERNAL_CORE_IOMGR_TCP_SERVER_H
+#ifndef GRPC_CORE_IOMGR_TCP_SERVER_H
+#define GRPC_CORE_IOMGR_TCP_SERVER_H
 
 #include "src/core/iomgr/closure.h"
 #include "src/core/iomgr/endpoint.h"
@@ -100,4 +100,4 @@ void grpc_tcp_server_shutdown_starting_add(grpc_tcp_server *s,
    a call (exec_ctx!=NULL) to shutdown_complete. */
 void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_TCP_SERVER_H */
+#endif /* GRPC_CORE_IOMGR_TCP_SERVER_H */
diff --git a/src/core/iomgr/tcp_windows.h b/src/core/iomgr/tcp_windows.h
index deb3e48293c6b3b917b50ddbc9beacbfc06d290a..78bc13389adff7fccc099c4686a99174a071a33e 100644
--- a/src/core/iomgr/tcp_windows.h
+++ b/src/core/iomgr/tcp_windows.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_TCP_WINDOWS_H
-#define GRPC_INTERNAL_CORE_IOMGR_TCP_WINDOWS_H
+#ifndef GRPC_CORE_IOMGR_TCP_WINDOWS_H
+#define GRPC_CORE_IOMGR_TCP_WINDOWS_H
 /*
    Low level TCP "bottom half" implementation, for use by transports built on
    top of a TCP connection.
@@ -54,4 +54,4 @@ grpc_endpoint *grpc_tcp_create(grpc_winsocket *socket, char *peer_string);
 
 int grpc_tcp_prepare_socket(SOCKET sock);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_TCP_WINDOWS_H */
+#endif /* GRPC_CORE_IOMGR_TCP_WINDOWS_H */
diff --git a/src/core/iomgr/time_averaged_stats.h b/src/core/iomgr/time_averaged_stats.h
index 4e9e3956c28cdaa9c057b04808a241ccd2d3637c..048e244bcc1de14f9128867f4073aee4faa5fec0 100644
--- a/src/core/iomgr/time_averaged_stats.h
+++ b/src/core/iomgr/time_averaged_stats.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_TIME_AVERAGED_STATS_H
-#define GRPC_INTERNAL_CORE_IOMGR_TIME_AVERAGED_STATS_H
+#ifndef GRPC_CORE_IOMGR_TIME_AVERAGED_STATS_H
+#define GRPC_CORE_IOMGR_TIME_AVERAGED_STATS_H
 
 /* This tracks a time-decaying weighted average.  It works by collecting
    batches of samples and then mixing their average into a time-decaying
@@ -85,4 +85,4 @@ void grpc_time_averaged_stats_add_sample(grpc_time_averaged_stats* stats,
    value. */
 double grpc_time_averaged_stats_update_average(grpc_time_averaged_stats* stats);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_TIME_AVERAGED_STATS_H */
+#endif /* GRPC_CORE_IOMGR_TIME_AVERAGED_STATS_H */
diff --git a/src/core/iomgr/timer.h b/src/core/iomgr/timer.h
index e239e884e7ba01bb13c56c33c174d02b51d42f32..63505df4273704704d6127e6f597864fc110425d 100644
--- a/src/core/iomgr/timer.h
+++ b/src/core/iomgr/timer.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_TIMER_H
-#define GRPC_INTERNAL_CORE_IOMGR_TIMER_H
+#ifndef GRPC_CORE_IOMGR_TIMER_H
+#define GRPC_CORE_IOMGR_TIMER_H
 
 #include "src/core/iomgr/iomgr.h"
 #include "src/core/iomgr/exec_ctx.h"
@@ -105,4 +105,4 @@ void grpc_timer_list_shutdown(grpc_exec_ctx *exec_ctx);
 
 void grpc_kick_poller(void);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_TIMER_H */
+#endif /* GRPC_CORE_IOMGR_TIMER_H */
diff --git a/src/core/iomgr/timer_heap.h b/src/core/iomgr/timer_heap.h
index 2d220f16774e7af149ca7c06471ede00eb8e5666..c2912ef45df1963beff0eb92408871e7b228aadb 100644
--- a/src/core/iomgr/timer_heap.h
+++ b/src/core/iomgr/timer_heap.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_TIMER_HEAP_H
-#define GRPC_INTERNAL_CORE_IOMGR_TIMER_HEAP_H
+#ifndef GRPC_CORE_IOMGR_TIMER_HEAP_H
+#define GRPC_CORE_IOMGR_TIMER_HEAP_H
 
 #include "src/core/iomgr/timer.h"
 
@@ -54,4 +54,4 @@ void grpc_timer_heap_pop(grpc_timer_heap *heap);
 
 int grpc_timer_heap_is_empty(grpc_timer_heap *heap);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_TIMER_HEAP_H */
+#endif /* GRPC_CORE_IOMGR_TIMER_HEAP_H */
diff --git a/src/core/iomgr/udp_server.h b/src/core/iomgr/udp_server.h
index a9d0489edfd13b44cabfc11e7a111b6f7a01c26f..1e59a92392d9ad9d192c4515eb30f5b88a234a25 100644
--- a/src/core/iomgr/udp_server.h
+++ b/src/core/iomgr/udp_server.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_UDP_SERVER_H
-#define GRPC_INTERNAL_CORE_IOMGR_UDP_SERVER_H
+#ifndef GRPC_CORE_IOMGR_UDP_SERVER_H
+#define GRPC_CORE_IOMGR_UDP_SERVER_H
 
 #include "src/core/iomgr/endpoint.h"
 #include "src/core/iomgr/fd_posix.h"
@@ -73,4 +73,4 @@ int grpc_udp_server_add_port(grpc_udp_server *s, const void *addr,
 void grpc_udp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_udp_server *server,
                              grpc_closure *on_done);
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_UDP_SERVER_H */
+#endif /* GRPC_CORE_IOMGR_UDP_SERVER_H */
diff --git a/src/core/iomgr/wakeup_fd_pipe.h b/src/core/iomgr/wakeup_fd_pipe.h
index 01a13a97c036e362e3f33791216f427bb56af388..eb3e02b482a86c6d8117e714abaf09ef81426e5a 100644
--- a/src/core/iomgr/wakeup_fd_pipe.h
+++ b/src/core/iomgr/wakeup_fd_pipe.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_WAKEUP_FD_PIPE_H
-#define GRPC_INTERNAL_CORE_IOMGR_WAKEUP_FD_PIPE_H
+#ifndef GRPC_CORE_IOMGR_WAKEUP_FD_PIPE_H
+#define GRPC_CORE_IOMGR_WAKEUP_FD_PIPE_H
 
 #include "src/core/iomgr/wakeup_fd_posix.h"
 
 extern grpc_wakeup_fd_vtable grpc_pipe_wakeup_fd_vtable;
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_WAKEUP_FD_PIPE_H */
+#endif /* GRPC_CORE_IOMGR_WAKEUP_FD_PIPE_H */
diff --git a/src/core/iomgr/wakeup_fd_posix.h b/src/core/iomgr/wakeup_fd_posix.h
index ffd60d1d4e68dcaee8d43a1e5dcfc085c446ed96..d7e3cf46733f9230aa5a6ff6e0e01baa7830e4b0 100644
--- a/src/core/iomgr/wakeup_fd_posix.h
+++ b/src/core/iomgr/wakeup_fd_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -59,8 +59,8 @@
  * 2. If the polling thread was awakened by a wakeup_fd event, call
  *    grpc_wakeup_fd_consume_wakeup() on it.
  */
-#ifndef GRPC_INTERNAL_CORE_IOMGR_WAKEUP_FD_POSIX_H
-#define GRPC_INTERNAL_CORE_IOMGR_WAKEUP_FD_POSIX_H
+#ifndef GRPC_CORE_IOMGR_WAKEUP_FD_POSIX_H
+#define GRPC_CORE_IOMGR_WAKEUP_FD_POSIX_H
 
 void grpc_wakeup_fd_global_init(void);
 void grpc_wakeup_fd_global_destroy(void);
@@ -98,4 +98,4 @@ void grpc_wakeup_fd_destroy(grpc_wakeup_fd* fd_info);
  * wakeup_fd_nospecial.c if no such implementation exists. */
 extern const grpc_wakeup_fd_vtable grpc_specialized_wakeup_fd_vtable;
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_WAKEUP_FD_POSIX_H */
+#endif /* GRPC_CORE_IOMGR_WAKEUP_FD_POSIX_H */
diff --git a/src/core/iomgr/workqueue.h b/src/core/iomgr/workqueue.h
index 36dd133468328e6b533fdfb6c061b7f49662019f..2ba1e5d9a20e3c234556bf1a5dc051908ffcd1cd 100644
--- a/src/core/iomgr/workqueue.h
+++ b/src/core/iomgr/workqueue.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_WORKQUEUE_H
-#define GRPC_INTERNAL_CORE_IOMGR_WORKQUEUE_H
+#ifndef GRPC_CORE_IOMGR_WORKQUEUE_H
+#define GRPC_CORE_IOMGR_WORKQUEUE_H
 
 #include "src/core/iomgr/iomgr.h"
 #include "src/core/iomgr/pollset.h"
@@ -80,4 +80,4 @@ void grpc_workqueue_add_to_pollset(grpc_exec_ctx *exec_ctx,
 void grpc_workqueue_push(grpc_workqueue *workqueue, grpc_closure *closure,
                          int success);
 
-#endif
+#endif /* GRPC_CORE_IOMGR_WORKQUEUE_H */
diff --git a/src/core/iomgr/workqueue_posix.h b/src/core/iomgr/workqueue_posix.h
index 68f195ee0d266892e0a39836e2cf4a30644761f6..89937b1ea812071c2f87c90a6adc2a1bb2a42ee3 100644
--- a/src/core/iomgr/workqueue_posix.h
+++ b/src/core/iomgr/workqueue_posix.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_WORKQUEUE_POSIX_H
-#define GRPC_INTERNAL_CORE_IOMGR_WORKQUEUE_POSIX_H
+#ifndef GRPC_CORE_IOMGR_WORKQUEUE_POSIX_H
+#define GRPC_CORE_IOMGR_WORKQUEUE_POSIX_H
 
 #include "src/core/iomgr/wakeup_fd_posix.h"
 
@@ -50,4 +50,4 @@ struct grpc_workqueue {
   grpc_closure read_closure;
 };
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_WORKQUEUE_POSIX_H */
+#endif /* GRPC_CORE_IOMGR_WORKQUEUE_POSIX_H */
diff --git a/src/core/iomgr/workqueue_windows.h b/src/core/iomgr/workqueue_windows.h
index 941f195f51403a46f18cb24e15de8e879b0fef19..7e8186921e71dde0e4785e6c3a1b30d23172ef42 100644
--- a/src/core/iomgr/workqueue_windows.h
+++ b/src/core/iomgr/workqueue_windows.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,7 +31,7 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_WORKQUEUE_WINDOWS_H
-#define GRPC_INTERNAL_CORE_IOMGR_WORKQUEUE_WINDOWS_H
+#ifndef GRPC_CORE_IOMGR_WORKQUEUE_WINDOWS_H
+#define GRPC_CORE_IOMGR_WORKQUEUE_WINDOWS_H
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_WORKQUEUE_WINDOWS_H */
+#endif /* GRPC_CORE_IOMGR_WORKQUEUE_WINDOWS_H */
diff --git a/src/core/json/json.h b/src/core/json/json.h
index c4df2998c3a9ea69b3fbc59baf58c4dfd3c408f9..aea9d5dadba6a576115d0bfe3354af3851b8a918 100644
--- a/src/core/json/json.h
+++ b/src/core/json/json.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_JSON_JSON_H
-#define GRPC_INTERNAL_CORE_JSON_JSON_H
+#ifndef GRPC_CORE_JSON_JSON_H
+#define GRPC_CORE_JSON_JSON_H
 
 #include <stdlib.h>
 
@@ -85,4 +85,4 @@ char *grpc_json_dump_to_string(grpc_json *json, int indent);
 grpc_json *grpc_json_create(grpc_json_type type);
 void grpc_json_destroy(grpc_json *json);
 
-#endif /* GRPC_INTERNAL_CORE_JSON_JSON_H */
+#endif /* GRPC_CORE_JSON_JSON_H */
diff --git a/src/core/json/json_common.h b/src/core/json/json_common.h
index 481695b38b8412c21235aa22c4cface56c70b344..7205a946850d65fd6c8a0782bfa71256bf4838f8 100644
--- a/src/core/json/json_common.h
+++ b/src/core/json/json_common.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_JSON_JSON_COMMON_H
-#define GRPC_INTERNAL_CORE_JSON_JSON_COMMON_H
+#ifndef GRPC_CORE_JSON_JSON_COMMON_H
+#define GRPC_CORE_JSON_JSON_COMMON_H
 
 /* The various json types. */
 typedef enum {
@@ -46,4 +46,4 @@ typedef enum {
   GRPC_JSON_TOP_LEVEL
 } grpc_json_type;
 
-#endif /* GRPC_INTERNAL_CORE_JSON_JSON_COMMON_H */
+#endif /* GRPC_CORE_JSON_JSON_COMMON_H */
diff --git a/src/core/json/json_reader.h b/src/core/json/json_reader.h
index 90b9f1f9fead95b693e9a7ac93286631f0b47e83..f25f44b2ef955bb99248dbc9f6f9774fd5f63edd 100644
--- a/src/core/json/json_reader.h
+++ b/src/core/json/json_reader.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_JSON_JSON_READER_H
-#define GRPC_INTERNAL_CORE_JSON_JSON_READER_H
+#ifndef GRPC_CORE_JSON_JSON_READER_H
+#define GRPC_CORE_JSON_JSON_READER_H
 
 #include <grpc/support/port_platform.h>
 #include "src/core/json/json_common.h"
@@ -157,4 +157,4 @@ void grpc_json_reader_init(grpc_json_reader *reader,
  */
 int grpc_json_reader_is_complete(grpc_json_reader *reader);
 
-#endif /* GRPC_INTERNAL_CORE_JSON_JSON_READER_H */
+#endif /* GRPC_CORE_JSON_JSON_READER_H */
diff --git a/src/core/json/json_writer.h b/src/core/json/json_writer.h
index 9ef04aab012a787e12572a2230db4c082dfddb09..c3921269503d807e371e401570c558ab08a2ffa4 100644
--- a/src/core/json/json_writer.h
+++ b/src/core/json/json_writer.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -43,8 +43,8 @@
  * a valid UTF-8 string overall.
  */
 
-#ifndef GRPC_INTERNAL_CORE_JSON_JSON_WRITER_H
-#define GRPC_INTERNAL_CORE_JSON_JSON_WRITER_H
+#ifndef GRPC_CORE_JSON_JSON_WRITER_H
+#define GRPC_CORE_JSON_JSON_WRITER_H
 
 #include <stdlib.h>
 
@@ -94,4 +94,4 @@ void grpc_json_writer_value_raw_with_len(grpc_json_writer *writer,
 void grpc_json_writer_value_string(grpc_json_writer *writer,
                                    const char *string);
 
-#endif /* GRPC_INTERNAL_CORE_JSON_JSON_WRITER_H */
+#endif /* GRPC_CORE_JSON_JSON_WRITER_H */
diff --git a/src/core/security/auth_filters.h b/src/core/security/auth_filters.h
index c179b54bec28af87f398fa679c4f248b87ba01aa..1154a1d914c4bc2f543ecdd6bf7d69cea00e87d0 100644
--- a/src/core/security/auth_filters.h
+++ b/src/core/security/auth_filters.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SECURITY_AUTH_FILTERS_H
-#define GRPC_INTERNAL_CORE_SECURITY_AUTH_FILTERS_H
+#ifndef GRPC_CORE_SECURITY_AUTH_FILTERS_H
+#define GRPC_CORE_SECURITY_AUTH_FILTERS_H
 
 #include "src/core/channel/channel_stack.h"
 
 extern const grpc_channel_filter grpc_client_auth_filter;
 extern const grpc_channel_filter grpc_server_auth_filter;
 
-#endif /* GRPC_INTERNAL_CORE_SECURITY_AUTH_FILTERS_H */
+#endif /* GRPC_CORE_SECURITY_AUTH_FILTERS_H */
diff --git a/src/core/security/b64.h b/src/core/security/b64.h
index 3e3b52112093c6fcc1426c982e31fbc646ff904f..d18f69563d32b914ff1f03151d02759f53733dda 100644
--- a/src/core/security/b64.h
+++ b/src/core/security/b64.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SECURITY_BASE64_H
-#define GRPC_INTERNAL_CORE_SECURITY_BASE64_H
+#ifndef GRPC_CORE_SECURITY_B64_H
+#define GRPC_CORE_SECURITY_B64_H
 
 #include <grpc/support/slice.h>
 
@@ -49,4 +49,4 @@ gpr_slice grpc_base64_decode(const char *b64, int url_safe);
 gpr_slice grpc_base64_decode_with_len(const char *b64, size_t b64_len,
                                       int url_safe);
 
-#endif /* GRPC_INTERNAL_CORE_SECURITY_BASE64_H */
+#endif /* GRPC_CORE_SECURITY_B64_H */
diff --git a/src/core/security/credentials.h b/src/core/security/credentials.h
index 0de4cd94689b2fb69c377c6febe13838fbb09705..133aa9d8d9f478acd1b12efffcd7d1329e0613f3 100644
--- a/src/core/security/credentials.h
+++ b/src/core/security/credentials.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SECURITY_CREDENTIALS_H
-#define GRPC_INTERNAL_CORE_SECURITY_CREDENTIALS_H
+#ifndef GRPC_CORE_SECURITY_CREDENTIALS_H
+#define GRPC_CORE_SECURITY_CREDENTIALS_H
 
 #include "src/core/transport/metadata_batch.h"
 #include <grpc/grpc.h>
@@ -373,4 +373,4 @@ typedef struct {
   grpc_credentials_md_store *plugin_md;
 } grpc_plugin_credentials;
 
-#endif /* GRPC_INTERNAL_CORE_SECURITY_CREDENTIALS_H */
+#endif /* GRPC_CORE_SECURITY_CREDENTIALS_H */
diff --git a/src/core/security/handshake.h b/src/core/security/handshake.h
index db8b3749215b95a1a79b0775d1a6e15d8e2eb64f..4872045874f6abbc82ae860e03a6eb821ab5a1e8 100644
--- a/src/core/security/handshake.h
+++ b/src/core/security/handshake.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SECURITY_HANDSHAKE_H
-#define GRPC_INTERNAL_CORE_SECURITY_HANDSHAKE_H
+#ifndef GRPC_CORE_SECURITY_HANDSHAKE_H
+#define GRPC_CORE_SECURITY_HANDSHAKE_H
 
 #include "src/core/iomgr/endpoint.h"
 #include "src/core/security/security_connector.h"
@@ -48,4 +48,4 @@ void grpc_do_security_handshake(grpc_exec_ctx *exec_ctx,
 
 void grpc_security_handshake_shutdown(grpc_exec_ctx *exec_ctx, void *handshake);
 
-#endif /* GRPC_INTERNAL_CORE_SECURITY_HANDSHAKE_H */
+#endif /* GRPC_CORE_SECURITY_HANDSHAKE_H */
diff --git a/src/core/security/json_token.h b/src/core/security/json_token.h
index 7e06864ff3adb5c013e2fab49c2619d2ebdb1b67..d183f9b3a358f53a25ca4cf01f8808fdd5eae647 100644
--- a/src/core/security/json_token.h
+++ b/src/core/security/json_token.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SECURITY_JSON_TOKEN_H
-#define GRPC_INTERNAL_CORE_SECURITY_JSON_TOKEN_H
+#ifndef GRPC_CORE_SECURITY_JSON_TOKEN_H
+#define GRPC_CORE_SECURITY_JSON_TOKEN_H
 
 #include <grpc/support/slice.h>
 #include <openssl/rsa.h>
@@ -115,4 +115,4 @@ grpc_auth_refresh_token grpc_auth_refresh_token_create_from_json(
 /* Destructs the object. */
 void grpc_auth_refresh_token_destruct(grpc_auth_refresh_token *refresh_token);
 
-#endif /* GRPC_INTERNAL_CORE_SECURITY_JSON_TOKEN_H */
+#endif /* GRPC_CORE_SECURITY_JSON_TOKEN_H */
diff --git a/src/core/security/jwt_verifier.h b/src/core/security/jwt_verifier.h
index 25613f03a07f14c1e099f77831b72db14a1ffb4f..d898d2193f7b9fa0d53e582485dca16f5c0d823c 100644
--- a/src/core/security/jwt_verifier.h
+++ b/src/core/security/jwt_verifier.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SECURITY_JWT_VERIFIER_H
-#define GRPC_INTERNAL_CORE_SECURITY_JWT_VERIFIER_H
+#ifndef GRPC_CORE_SECURITY_JWT_VERIFIER_H
+#define GRPC_CORE_SECURITY_JWT_VERIFIER_H
 
 #include "src/core/iomgr/pollset.h"
 #include "src/core/json/json.h"
@@ -133,4 +133,4 @@ grpc_jwt_claims *grpc_jwt_claims_from_json(grpc_json *json, gpr_slice buffer);
 grpc_jwt_verifier_status grpc_jwt_claims_check(const grpc_jwt_claims *claims,
                                                const char *audience);
 
-#endif /* GRPC_INTERNAL_CORE_SECURITY_JWT_VERIFIER_H */
+#endif /* GRPC_CORE_SECURITY_JWT_VERIFIER_H */
diff --git a/src/core/security/secure_endpoint.h b/src/core/security/secure_endpoint.h
index c563bdd9c505f42241ffbace849ce34c774efa8f..5176ef20596f4649205eb78c0a740eaece9060f0 100644
--- a/src/core/security/secure_endpoint.h
+++ b/src/core/security/secure_endpoint.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SECURITY_SECURE_ENDPOINT_H
-#define GRPC_INTERNAL_CORE_SECURITY_SECURE_ENDPOINT_H
+#ifndef GRPC_CORE_SECURITY_SECURE_ENDPOINT_H
+#define GRPC_CORE_SECURITY_SECURE_ENDPOINT_H
 
 #include "src/core/iomgr/endpoint.h"
 #include <grpc/support/slice.h>
@@ -46,4 +46,4 @@ grpc_endpoint *grpc_secure_endpoint_create(
     struct tsi_frame_protector *protector, grpc_endpoint *to_wrap,
     gpr_slice *leftover_slices, size_t leftover_nslices);
 
-#endif /* GRPC_INTERNAL_CORE_SECURITY_SECURE_ENDPOINT_H */
+#endif /* GRPC_CORE_SECURITY_SECURE_ENDPOINT_H */
diff --git a/src/core/security/security_connector.h b/src/core/security/security_connector.h
index 1e35d3f9b7ce8f5f98ab1ff8b59bb04650159914..6f915ebb9d38084e9f21b2e5d1bfcf9cbc711c04 100644
--- a/src/core/security/security_connector.h
+++ b/src/core/security/security_connector.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SECURITY_SECURITY_CONNECTOR_H
-#define GRPC_INTERNAL_CORE_SECURITY_SECURITY_CONNECTOR_H
+#ifndef GRPC_CORE_SECURITY_SECURITY_CONNECTOR_H
+#define GRPC_CORE_SECURITY_SECURITY_CONNECTOR_H
 
 #include <grpc/grpc_security.h>
 #include "src/core/iomgr/endpoint.h"
@@ -263,4 +263,4 @@ tsi_peer tsi_shallow_peer_from_ssl_auth_context(
     const grpc_auth_context *auth_context);
 void tsi_shallow_peer_destruct(tsi_peer *peer);
 
-#endif /* GRPC_INTERNAL_CORE_SECURITY_SECURITY_CONNECTOR_H */
+#endif /* GRPC_CORE_SECURITY_SECURITY_CONNECTOR_H */
diff --git a/src/core/security/security_context.h b/src/core/security/security_context.h
index 794258edbcb1470474e9154416d2ddf17a35a2d0..61601f538b7a93e4daabe33b035a3dee091393b3 100644
--- a/src/core/security/security_context.h
+++ b/src/core/security/security_context.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SECURITY_SECURITY_CONTEXT_H
-#define GRPC_INTERNAL_CORE_SECURITY_SECURITY_CONTEXT_H
+#ifndef GRPC_CORE_SECURITY_SECURITY_CONTEXT_H
+#define GRPC_CORE_SECURITY_SECURITY_CONTEXT_H
 
 #include "src/core/iomgr/pollset.h"
 #include "src/core/security/credentials.h"
@@ -111,4 +111,4 @@ grpc_auth_context *grpc_auth_context_from_arg(const grpc_arg *arg);
 grpc_auth_context *grpc_find_auth_context_in_args(
     const grpc_channel_args *args);
 
-#endif /* GRPC_INTERNAL_CORE_SECURITY_SECURITY_CONTEXT_H */
+#endif /* GRPC_CORE_SECURITY_SECURITY_CONTEXT_H */
diff --git a/src/core/statistics/census_interface.h b/src/core/statistics/census_interface.h
index c43acbd317fbbd50f3dc0f9f82c9711301f79990..ce8ff92cd4e384d5269f63bdc6e57b0396e69be7 100644
--- a/src/core/statistics/census_interface.h
+++ b/src/core/statistics/census_interface.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_STATISTICS_CENSUS_INTERFACE_H
-#define GRPC_INTERNAL_CORE_STATISTICS_CENSUS_INTERFACE_H
+#ifndef GRPC_CORE_STATISTICS_CENSUS_INTERFACE_H
+#define GRPC_CORE_STATISTICS_CENSUS_INTERFACE_H
 
 #include <grpc/support/port_platform.h>
 
@@ -73,4 +73,4 @@ census_op_id census_tracing_start_op(void);
 /* Ends tracing. Calling this function will invalidate the input op_id. */
 void census_tracing_end_op(census_op_id op_id);
 
-#endif /* GRPC_INTERNAL_CORE_STATISTICS_CENSUS_INTERFACE_H */
+#endif /* GRPC_CORE_STATISTICS_CENSUS_INTERFACE_H */
diff --git a/src/core/statistics/census_log.h b/src/core/statistics/census_log.h
index 356437c346e948aed78cfe346e2127e2da1dec5d..e7ce0d4433fa27c0ee1d8b19287b8bd65f0b2741 100644
--- a/src/core/statistics/census_log.h
+++ b/src/core/statistics/census_log.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_STATISTICS_CENSUS_LOG_H
-#define GRPC_INTERNAL_CORE_STATISTICS_CENSUS_LOG_H
+#ifndef GRPC_CORE_STATISTICS_CENSUS_LOG_H
+#define GRPC_CORE_STATISTICS_CENSUS_LOG_H
 
 #include <stddef.h>
 
@@ -88,4 +88,4 @@ size_t census_log_remaining_space(void);
    out-of-space. */
 int census_log_out_of_space_count(void);
 
-#endif /* GRPC_INTERNAL_CORE_STATISTICS_CENSUS_LOG_H */
+#endif /* GRPC_CORE_STATISTICS_CENSUS_LOG_H */
diff --git a/src/core/statistics/census_rpc_stats.h b/src/core/statistics/census_rpc_stats.h
index 8bdbc494903872d80ca1f22baf0a1e82aeee4fb5..4cf17d2e52c7a0d7b57ad467209449cf6d816460 100644
--- a/src/core/statistics/census_rpc_stats.h
+++ b/src/core/statistics/census_rpc_stats.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_STATISTICS_CENSUS_RPC_STATS_H
-#define GRPC_INTERNAL_CORE_STATISTICS_CENSUS_RPC_STATS_H
+#ifndef GRPC_CORE_STATISTICS_CENSUS_RPC_STATS_H
+#define GRPC_CORE_STATISTICS_CENSUS_RPC_STATS_H
 
 #include "src/core/statistics/census_interface.h"
 #include <grpc/support/port_platform.h>
@@ -98,4 +98,4 @@ void census_stats_store_shutdown(void);
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_STATISTICS_CENSUS_RPC_STATS_H */
+#endif /* GRPC_CORE_STATISTICS_CENSUS_RPC_STATS_H */
diff --git a/src/core/statistics/census_tracing.h b/src/core/statistics/census_tracing.h
index bb3f2556d20349e400905c2b22e32655cbaa397f..b611e95bf4a688c666aafd00b74ebbe17e181e38 100644
--- a/src/core/statistics/census_tracing.h
+++ b/src/core/statistics/census_tracing.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_STATISTICS_CENSUS_TRACING_H
-#define GRPC_INTERNAL_CORE_STATISTICS_CENSUS_TRACING_H
+#ifndef GRPC_CORE_STATISTICS_CENSUS_TRACING_H
+#define GRPC_CORE_STATISTICS_CENSUS_TRACING_H
 
 #include <grpc/support/time.h>
 #include "src/core/statistics/census_rpc_stats.h"
@@ -93,4 +93,4 @@ census_trace_obj **census_get_active_ops(int *num_active_ops);
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_STATISTICS_CENSUS_TRACING_H */
+#endif /* GRPC_CORE_STATISTICS_CENSUS_TRACING_H */
diff --git a/src/core/statistics/hash_table.h b/src/core/statistics/hash_table.h
index d9860a909f0afda7ed56816904521dbfc8922116..f4bf2ba49afc79bc1360a0aad309963393dbd21b 100644
--- a/src/core/statistics/hash_table.h
+++ b/src/core/statistics/hash_table.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_STATISTICS_HASH_TABLE_H
-#define GRPC_INTERNAL_CORE_STATISTICS_HASH_TABLE_H
+#ifndef GRPC_CORE_STATISTICS_HASH_TABLE_H
+#define GRPC_CORE_STATISTICS_HASH_TABLE_H
 
 #include <stddef.h>
 
@@ -128,4 +128,4 @@ typedef void (*census_ht_itr_cb)(census_ht_key key, const void *val_ptr,
    should not invalidate data entries. */
 uint64_t census_ht_for_all(const census_ht *ht, census_ht_itr_cb);
 
-#endif /* GRPC_INTERNAL_CORE_STATISTICS_HASH_TABLE_H */
+#endif /* GRPC_CORE_STATISTICS_HASH_TABLE_H */
diff --git a/src/core/statistics/window_stats.h b/src/core/statistics/window_stats.h
index f4732e96a02e4083e9bbca550ae84436e7f717e0..774277180f60238e93cb9159028dbecd69160fc2 100644
--- a/src/core/statistics/window_stats.h
+++ b/src/core/statistics/window_stats.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_STATISTICS_WINDOW_STATS_H
-#define GRPC_INTERNAL_CORE_STATISTICS_WINDOW_STATS_H
+#ifndef GRPC_CORE_STATISTICS_WINDOW_STATS_H
+#define GRPC_CORE_STATISTICS_WINDOW_STATS_H
 
 #include <grpc/support/time.h>
 
@@ -170,4 +170,4 @@ void census_window_stats_get_sums(const struct census_window_stats *wstats,
    assertion failure). This function is thread-compatible. */
 void census_window_stats_destroy(struct census_window_stats *wstats);
 
-#endif /* GRPC_INTERNAL_CORE_STATISTICS_WINDOW_STATS_H */
+#endif /* GRPC_CORE_STATISTICS_WINDOW_STATS_H */
diff --git a/src/core/support/backoff.c b/src/core/support/backoff.c
new file mode 100644
index 0000000000000000000000000000000000000000..745821964560193b03a7acd0b69e33d3f4c82805
--- /dev/null
+++ b/src/core/support/backoff.c
@@ -0,0 +1,71 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/support/backoff.h"
+
+#include <grpc/support/useful.h>
+
+void gpr_backoff_init(gpr_backoff *backoff, double multiplier, double jitter,
+                      int64_t min_timeout_millis, int64_t max_timeout_millis) {
+  backoff->multiplier = multiplier;
+  backoff->jitter = jitter;
+  backoff->min_timeout_millis = min_timeout_millis;
+  backoff->max_timeout_millis = max_timeout_millis;
+  backoff->rng_state = (uint32_t)gpr_now(GPR_CLOCK_REALTIME).tv_nsec;
+}
+
+gpr_timespec gpr_backoff_begin(gpr_backoff *backoff, gpr_timespec now) {
+  backoff->current_timeout_millis = backoff->min_timeout_millis;
+  return gpr_time_add(
+      now, gpr_time_from_millis(backoff->current_timeout_millis, GPR_TIMESPAN));
+}
+
+/* Generate a random number between 0 and 1. */
+static double generate_uniform_random_number(uint32_t *rng_state) {
+  *rng_state = (1103515245 * *rng_state + 12345) % ((uint32_t)1 << 31);
+  return *rng_state / (double)((uint32_t)1 << 31);
+}
+
+gpr_timespec gpr_backoff_step(gpr_backoff *backoff, gpr_timespec now) {
+  double new_timeout_millis =
+      backoff->multiplier * (double)backoff->current_timeout_millis;
+  double jitter_range = backoff->jitter * new_timeout_millis;
+  double jitter =
+      (2 * generate_uniform_random_number(&backoff->rng_state) - 1) *
+      jitter_range;
+  backoff->current_timeout_millis =
+      GPR_CLAMP((int64_t)(new_timeout_millis + jitter),
+                backoff->min_timeout_millis, backoff->max_timeout_millis);
+  return gpr_time_add(
+      now, gpr_time_from_millis(backoff->current_timeout_millis, GPR_TIMESPAN));
+}
diff --git a/src/core/support/backoff.h b/src/core/support/backoff.h
new file mode 100644
index 0000000000000000000000000000000000000000..f7730fde2ae8f28c85839b1c6fbc2f1f827579a2
--- /dev/null
+++ b/src/core/support/backoff.h
@@ -0,0 +1,65 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_SUPPORT_BACKOFF_H
+#define GRPC_CORE_SUPPORT_BACKOFF_H
+
+#include <grpc/support/time.h>
+
+typedef struct {
+  /// const: multiplier between retry attempts
+  double multiplier;
+  /// const: amount to randomize backoffs
+  double jitter;
+  /// const: minimum time between retries in milliseconds
+  int64_t min_timeout_millis;
+  /// const: maximum time between retries in milliseconds
+  int64_t max_timeout_millis;
+
+  /// random number generator
+  uint32_t rng_state;
+
+  /// current retry timeout in milliseconds
+  int64_t current_timeout_millis;
+} gpr_backoff;
+
+/// Initialize backoff machinery - does not need to be destroyed
+void gpr_backoff_init(gpr_backoff *backoff, double multiplier, double jitter,
+                      int64_t min_timeout_millis, int64_t max_timeout_millis);
+
+/// Begin retry loop: returns a timespec for the NEXT retry
+gpr_timespec gpr_backoff_begin(gpr_backoff *backoff, gpr_timespec now);
+/// Step a retry loop: returns a timespec for the NEXT retry
+gpr_timespec gpr_backoff_step(gpr_backoff *backoff, gpr_timespec now);
+
+#endif /* GRPC_CORE_SUPPORT_BACKOFF_H */
diff --git a/src/core/support/block_annotate.h b/src/core/support/block_annotate.h
index 3cd8eee272d3f3556afa9b86b49c26634b592517..79a18039f4ccf602da5e8cd692bf91dc77b018a2 100644
--- a/src/core/support/block_annotate.h
+++ b/src/core/support/block_annotate.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SUPPORT_BLOCK_ANNOTATE_H
-#define GRPC_INTERNAL_CORE_SUPPORT_BLOCK_ANNOTATE_H
+#ifndef GRPC_CORE_SUPPORT_BLOCK_ANNOTATE_H
+#define GRPC_CORE_SUPPORT_BLOCK_ANNOTATE_H
 
 /* These annotations identify the beginning and end of regions where
    the code may block for reasons other than synchronization functions.
@@ -45,4 +45,4 @@
   do {                                      \
   } while (0)
 
-#endif /* GRPC_INTERNAL_CORE_SUPPORT_BLOCK_ANNOTATE_H */
+#endif /* GRPC_CORE_SUPPORT_BLOCK_ANNOTATE_H */
diff --git a/src/core/support/env.h b/src/core/support/env.h
index 24172d86737eceb6ccfbd4f4bb854b0d2bbbe4f8..29024569473326e925f6f83c61beb9d51e82e09f 100644
--- a/src/core/support/env.h
+++ b/src/core/support/env.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SUPPORT_ENV_H
-#define GRPC_INTERNAL_CORE_SUPPORT_ENV_H
+#ifndef GRPC_CORE_SUPPORT_ENV_H
+#define GRPC_CORE_SUPPORT_ENV_H
 
 #include <stdio.h>
 
@@ -57,4 +57,4 @@ void gpr_setenv(const char *name, const char *value);
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_SUPPORT_ENV_H */
+#endif /* GRPC_CORE_SUPPORT_ENV_H */
diff --git a/src/core/support/load_file.h b/src/core/support/load_file.h
index 746319a50d22bbafa4fd685efa5cafd6c1920ebb..5896654e9a0c4078b68e5790d64eb36740ab3084 100644
--- a/src/core/support/load_file.h
+++ b/src/core/support/load_file.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SUPPORT_LOAD_FILE_H
-#define GRPC_INTERNAL_CORE_SUPPORT_LOAD_FILE_H
+#ifndef GRPC_CORE_SUPPORT_LOAD_FILE_H
+#define GRPC_CORE_SUPPORT_LOAD_FILE_H
 
 #include <stdio.h>
 
@@ -52,4 +52,4 @@ gpr_slice gpr_load_file(const char *filename, int add_null_terminator,
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_SUPPORT_LOAD_FILE_H */
+#endif /* GRPC_CORE_SUPPORT_LOAD_FILE_H */
diff --git a/src/core/support/murmur_hash.h b/src/core/support/murmur_hash.h
index 0bf04f731ad85588e5e6d2d5eeefdc4e11c9065f..0f0b399e5dc9386cb358dc8ecbaf6ce3754688a4 100644
--- a/src/core/support/murmur_hash.h
+++ b/src/core/support/murmur_hash.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SUPPORT_MURMUR_HASH_H
-#define GRPC_INTERNAL_CORE_SUPPORT_MURMUR_HASH_H
+#ifndef GRPC_CORE_SUPPORT_MURMUR_HASH_H
+#define GRPC_CORE_SUPPORT_MURMUR_HASH_H
 
 #include <grpc/support/port_platform.h>
 
@@ -41,4 +41,4 @@
 /* compute the hash of key (length len) */
 uint32_t gpr_murmur_hash3(const void *key, size_t len, uint32_t seed);
 
-#endif /* GRPC_INTERNAL_CORE_SUPPORT_MURMUR_HASH_H */
+#endif /* GRPC_CORE_SUPPORT_MURMUR_HASH_H */
diff --git a/src/core/support/stack_lockfree.h b/src/core/support/stack_lockfree.h
index ca58dd007a2ef7b4adb575b57de1bdd61ce8d516..d6fd06d67cb445de1e08c0b0254473271394f3be 100644
--- a/src/core/support/stack_lockfree.h
+++ b/src/core/support/stack_lockfree.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SUPPORT_STACK_LOCKFREE_H
-#define GRPC_INTERNAL_CORE_SUPPORT_STACK_LOCKFREE_H
+#ifndef GRPC_CORE_SUPPORT_STACK_LOCKFREE_H
+#define GRPC_CORE_SUPPORT_STACK_LOCKFREE_H
 
 #include <stddef.h>
 
@@ -50,4 +50,4 @@ int gpr_stack_lockfree_push(gpr_stack_lockfree *, int entry);
 /* Returns -1 on empty or the actual entry number */
 int gpr_stack_lockfree_pop(gpr_stack_lockfree *stack);
 
-#endif /* GRPC_INTERNAL_CORE_SUPPORT_STACK_LOCKFREE_H */
+#endif /* GRPC_CORE_SUPPORT_STACK_LOCKFREE_H */
diff --git a/src/core/support/string.h b/src/core/support/string.h
index e6755de106cbc41e5954c0012d4db8f1b597ae7c..a367ed7cd80a1f91a1fc5f1d968da9ce36885725 100644
--- a/src/core/support/string.h
+++ b/src/core/support/string.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SUPPORT_STRING_H
-#define GRPC_INTERNAL_CORE_SUPPORT_STRING_H
+#ifndef GRPC_CORE_SUPPORT_STRING_H
+#define GRPC_CORE_SUPPORT_STRING_H
 
 #include <stddef.h>
 
@@ -118,4 +118,4 @@ char *gpr_strvec_flatten(gpr_strvec *strs, size_t *total_length);
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_SUPPORT_STRING_H */
+#endif /* GRPC_CORE_SUPPORT_STRING_H */
diff --git a/src/core/support/string_win32.h b/src/core/support/string_win32.h
index e3043656fbaa510dc6bc43c8956c3f14f412f9fd..c9ae8d9932596c94689b41df77e6018cbb3cd5e4 100644
--- a/src/core/support/string_win32.h
+++ b/src/core/support/string_win32.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SUPPORT_STRING_WIN32_H
-#define GRPC_INTERNAL_CORE_SUPPORT_STRING_WIN32_H
+#ifndef GRPC_CORE_SUPPORT_STRING_WIN32_H
+#define GRPC_CORE_SUPPORT_STRING_WIN32_H
 
 #include <grpc/support/port_platform.h>
 
@@ -44,4 +44,4 @@ LPSTR gpr_tchar_to_char(LPCTSTR input);
 
 #endif /* GPR_WIN32 */
 
-#endif /* GRPC_INTERNAL_CORE_SUPPORT_STRING_WIN32_H */
+#endif /* GRPC_CORE_SUPPORT_STRING_WIN32_H */
diff --git a/src/core/support/thd_internal.h b/src/core/support/thd_internal.h
index 1508c4691f249c36326b380755add3db396d8595..33b904e59b1666e36bdc75c5404b66e4f477787a 100644
--- a/src/core/support/thd_internal.h
+++ b/src/core/support/thd_internal.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,9 +31,9 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SUPPORT_THD_INTERNAL_H
-#define GRPC_INTERNAL_CORE_SUPPORT_THD_INTERNAL_H
+#ifndef GRPC_CORE_SUPPORT_THD_INTERNAL_H
+#define GRPC_CORE_SUPPORT_THD_INTERNAL_H
 
 /* Internal interfaces between modules within the gpr support library.  */
 
-#endif /* GRPC_INTERNAL_CORE_SUPPORT_THD_INTERNAL_H */
+#endif /* GRPC_CORE_SUPPORT_THD_INTERNAL_H */
diff --git a/src/core/support/time_precise.h b/src/core/support/time_precise.h
index 80c5000123d6bf7767a8a28dac682121af332e48..871c99a6238ec398f764d50848757feb8e78cf26 100644
--- a/src/core/support/time_precise.h
+++ b/src/core/support/time_precise.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_CORE_SUPPORT_TIME_PRECISE_H_
-#define GRPC_CORE_SUPPORT_TIME_PRECISE_H_
+#ifndef GRPC_CORE_SUPPORT_TIME_PRECISE_H
+#define GRPC_CORE_SUPPORT_TIME_PRECISE_H
 
 #include <grpc/support/time.h>
 
 void gpr_precise_clock_init(void);
 void gpr_precise_clock_now(gpr_timespec *clk);
 
-#endif /* GRPC_CORE_SUPPORT_TIME_PRECISE_ */
+#endif /* GRPC_CORE_SUPPORT_TIME_PRECISE_H */
diff --git a/src/core/support/tmpfile.h b/src/core/support/tmpfile.h
index cecc71e2429c520c53ee5efbcbfbcc826bcee113..df6f8692bbedb3df6ae57b5b9f45e09659ae2ec9 100644
--- a/src/core/support/tmpfile.h
+++ b/src/core/support/tmpfile.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SUPPORT_TMPFILE_H
-#define GRPC_INTERNAL_CORE_SUPPORT_TMPFILE_H
+#ifndef GRPC_CORE_SUPPORT_TMPFILE_H
+#define GRPC_CORE_SUPPORT_TMPFILE_H
 
 #include <stdio.h>
 
@@ -52,4 +52,4 @@ FILE *gpr_tmpfile(const char *prefix, char **tmp_filename);
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_SUPPORT_TMPFILE_H */
+#endif /* GRPC_CORE_SUPPORT_TMPFILE_H */
diff --git a/src/core/surface/api_trace.h b/src/core/surface/api_trace.h
index 82bbf3b62b3a2231cc7602b249f4d48fada7ad8a..29a9b2d79cebea90e67e824af40ab3abcadf695f 100644
--- a/src/core/surface/api_trace.h
+++ b/src/core/surface/api_trace.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SURFACE_API_TRACE_H
-#define GRPC_INTERNAL_CORE_SURFACE_API_TRACE_H
+#ifndef GRPC_CORE_SURFACE_API_TRACE_H
+#define GRPC_CORE_SURFACE_API_TRACE_H
 
 #include "src/core/debug/trace.h"
 #include <grpc/support/log.h>
@@ -62,4 +62,4 @@ extern int grpc_api_trace;
     gpr_log(GPR_INFO, fmt GRPC_API_TRACE_UNWRAP##nargs args); \
   }
 
-#endif /* GRPC_INTERNAL_CORE_SURFACE_API_TRACE_H */
+#endif /* GRPC_CORE_SURFACE_API_TRACE_H */
diff --git a/src/core/surface/call.h b/src/core/surface/call.h
index 0b3f543fe4b3731eef93b65ef65f6b12742a2b82..d2edf03d45cd7c64e67211b33f547db28b29bcdb 100644
--- a/src/core/surface/call.h
+++ b/src/core/surface/call.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SURFACE_CALL_H
-#define GRPC_INTERNAL_CORE_SURFACE_CALL_H
+#ifndef GRPC_CORE_SURFACE_CALL_H
+#define GRPC_CORE_SURFACE_CALL_H
 
 #include "src/core/channel/channel_stack.h"
 #include "src/core/channel/context.h"
@@ -113,4 +113,4 @@ grpc_compression_algorithm grpc_call_compression_for_level(
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_SURFACE_CALL_H */
+#endif /* GRPC_CORE_SURFACE_CALL_H */
diff --git a/src/core/surface/call_test_only.h b/src/core/surface/call_test_only.h
index b57c95c64a5b9a0c55c028672bf07d4b7c50c6d7..fdc43a383ba3273dc4127cc31c9d5ec30c7b1b8f 100644
--- a/src/core/surface/call_test_only.h
+++ b/src/core/surface/call_test_only.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SURFACE_CALL_TEST_ONLY_H
-#define GRPC_INTERNAL_CORE_SURFACE_CALL_TEST_ONLY_H
+#ifndef GRPC_CORE_SURFACE_CALL_TEST_ONLY_H
+#define GRPC_CORE_SURFACE_CALL_TEST_ONLY_H
 
 #include <grpc/grpc.h>
 
@@ -61,4 +61,4 @@ uint32_t grpc_call_test_only_get_encodings_accepted_by_peer(grpc_call *call);
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_SURFACE_CALL_TEST_ONLY_H */
+#endif /* GRPC_CORE_SURFACE_CALL_TEST_ONLY_H */
diff --git a/src/core/surface/channel.h b/src/core/surface/channel.h
index 00240c637fdcf5b67eb24cf47c4e5c653e36b7d9..d5bc691d9a838b1fc9de6fcccc7c76fb5122b252 100644
--- a/src/core/surface/channel.h
+++ b/src/core/surface/channel.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SURFACE_CHANNEL_H
-#define GRPC_INTERNAL_CORE_SURFACE_CHANNEL_H
+#ifndef GRPC_CORE_SURFACE_CHANNEL_H
+#define GRPC_CORE_SURFACE_CHANNEL_H
 
 #include "src/core/channel/channel_stack.h"
 #include "src/core/client_config/subchannel_factory.h"
@@ -71,4 +71,4 @@ void grpc_channel_internal_unref(grpc_exec_ctx *exec_ctx,
   grpc_channel_internal_unref(exec_ctx, channel)
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_SURFACE_CHANNEL_H */
+#endif /* GRPC_CORE_SURFACE_CHANNEL_H */
diff --git a/src/core/surface/completion_queue.h b/src/core/surface/completion_queue.h
index 27ef90f2d58a5027e65983332f85c26a504ac7b9..07f6d0c8f6c48ac6bfc971f20ebc8b471cd4d1cb 100644
--- a/src/core/surface/completion_queue.h
+++ b/src/core/surface/completion_queue.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SURFACE_COMPLETION_QUEUE_H
-#define GRPC_INTERNAL_CORE_SURFACE_COMPLETION_QUEUE_H
+#ifndef GRPC_CORE_SURFACE_COMPLETION_QUEUE_H
+#define GRPC_CORE_SURFACE_COMPLETION_QUEUE_H
 
 /* Internal API for completion queues */
 
@@ -88,4 +88,4 @@ int grpc_cq_is_server_cq(grpc_completion_queue *cc);
 void grpc_cq_global_init(void);
 void grpc_cq_global_shutdown(void);
 
-#endif /* GRPC_INTERNAL_CORE_SURFACE_COMPLETION_QUEUE_H */
+#endif /* GRPC_CORE_SURFACE_COMPLETION_QUEUE_H */
diff --git a/src/core/surface/event_string.h b/src/core/surface/event_string.h
index 07c474e3a021a4a42ef976692ce13258fcb7a572..d0598ceccaed6f422a5489abc01cf3c6e01c94a0 100644
--- a/src/core/surface/event_string.h
+++ b/src/core/surface/event_string.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SURFACE_EVENT_STRING_H
-#define GRPC_INTERNAL_CORE_SURFACE_EVENT_STRING_H
+#ifndef GRPC_CORE_SURFACE_EVENT_STRING_H
+#define GRPC_CORE_SURFACE_EVENT_STRING_H
 
 #include <grpc/grpc.h>
 
 /* Returns a string describing an event. Must be later freed with gpr_free() */
 char *grpc_event_string(grpc_event *ev);
 
-#endif /* GRPC_INTERNAL_CORE_SURFACE_EVENT_STRING_H */
+#endif /* GRPC_CORE_SURFACE_EVENT_STRING_H */
diff --git a/src/core/surface/init.h b/src/core/surface/init.h
index 771c30f41257848118b5faf2dce2e07230f73a38..dddabbc8ceb830489825ed60649f8e6a5ea2aa9a 100644
--- a/src/core/surface/init.h
+++ b/src/core/surface/init.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SURFACE_INIT_H
-#define GRPC_INTERNAL_CORE_SURFACE_INIT_H
+#ifndef GRPC_CORE_SURFACE_INIT_H
+#define GRPC_CORE_SURFACE_INIT_H
 
 void grpc_security_pre_init(void);
 int grpc_is_initialized(void);
 
-#endif /* GRPC_INTERNAL_CORE_SURFACE_INIT_H */
+#endif /* GRPC_CORE_SURFACE_INIT_H */
diff --git a/src/core/surface/server.h b/src/core/surface/server.h
index a957fdb3605fb9f78958af6f78df442baedfb543..9ddcb01ae9f04eeb62a358b14b349002f5f2cecf 100644
--- a/src/core/surface/server.h
+++ b/src/core/surface/server.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SURFACE_SERVER_H
-#define GRPC_INTERNAL_CORE_SURFACE_SERVER_H
+#ifndef GRPC_CORE_SURFACE_SERVER_H
+#define GRPC_CORE_SURFACE_SERVER_H
 
 #include "src/core/channel/channel_stack.h"
 #include <grpc/grpc.h>
@@ -64,4 +64,4 @@ const grpc_channel_args *grpc_server_get_channel_args(grpc_server *server);
 
 int grpc_server_has_open_connections(grpc_server *server);
 
-#endif /* GRPC_INTERNAL_CORE_SURFACE_SERVER_H */
+#endif /* GRPC_CORE_SURFACE_SERVER_H */
diff --git a/src/core/surface/surface_trace.h b/src/core/surface/surface_trace.h
index 93b2859ac5b273588b4bf7cbee52ecbda9ea5e3f..ed820ebd053d0a80899280e5017230f9f253a6e1 100644
--- a/src/core/surface/surface_trace.h
+++ b/src/core/surface/surface_trace.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_SURFACE_SURFACE_TRACE_H
-#define GRPC_INTERNAL_CORE_SURFACE_SURFACE_TRACE_H
+#ifndef GRPC_CORE_SURFACE_SURFACE_TRACE_H
+#define GRPC_CORE_SURFACE_SURFACE_TRACE_H
 
 #include "src/core/debug/trace.h"
 #include "src/core/surface/api_trace.h"
@@ -45,4 +45,4 @@
     gpr_free(_ev);                                      \
   }
 
-#endif /* GRPC_INTERNAL_CORE_SURFACE_SURFACE_TRACE_H */
+#endif /* GRPC_CORE_SURFACE_SURFACE_TRACE_H */
diff --git a/src/core/transport/byte_stream.h b/src/core/transport/byte_stream.h
index d2e51e7b45e1da39576bc2268e110f11e8fce126..b8d0ade2b5c32d1884c352707a29698d6b219757 100644
--- a/src/core/transport/byte_stream.h
+++ b/src/core/transport/byte_stream.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_BYTE_STREAM_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_BYTE_STREAM_H
+#ifndef GRPC_CORE_TRANSPORT_BYTE_STREAM_H
+#define GRPC_CORE_TRANSPORT_BYTE_STREAM_H
 
 #include "src/core/iomgr/exec_ctx.h"
 #include <grpc/support/slice_buffer.h>
@@ -86,4 +86,4 @@ void grpc_slice_buffer_stream_init(grpc_slice_buffer_stream *stream,
                                    gpr_slice_buffer *slice_buffer,
                                    uint32_t flags);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_BYTE_STREAM_H */
+#endif /* GRPC_CORE_TRANSPORT_BYTE_STREAM_H */
diff --git a/src/core/transport/chttp2/alpn.h b/src/core/transport/chttp2/alpn.h
index f38b4c3167e0ededf9c4353e4eaf34cfc92af916..68010e3155d6c247cb2361ca1c207f3e030ba54b 100644
--- a/src/core/transport/chttp2/alpn.h
+++ b/src/core/transport/chttp2/alpn.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_ALPN_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_ALPN_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_ALPN_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_ALPN_H
 
 #include <string.h>
 
@@ -46,4 +46,4 @@ size_t grpc_chttp2_num_alpn_versions(void);
  * grpc_chttp2_num_alpn_versions()) */
 const char *grpc_chttp2_get_alpn_version_index(size_t i);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_ALPN_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_ALPN_H */
diff --git a/src/core/transport/chttp2/bin_encoder.h b/src/core/transport/chttp2/bin_encoder.h
index 036fddf9981e103297cc01ae5a7485051a5c2225..edb6f2dad1b15842cf42702af41fb2c541daef0f 100644
--- a/src/core/transport/chttp2/bin_encoder.h
+++ b/src/core/transport/chttp2/bin_encoder.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_BIN_ENCODER_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_BIN_ENCODER_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_BIN_ENCODER_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_BIN_ENCODER_H
 
 #include <grpc/support/slice.h>
 
@@ -51,4 +51,4 @@ gpr_slice grpc_chttp2_huffman_compress(gpr_slice input);
    return y; */
 gpr_slice grpc_chttp2_base64_encode_and_huffman_compress(gpr_slice input);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_BIN_ENCODER_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_BIN_ENCODER_H */
diff --git a/src/core/transport/chttp2/frame.h b/src/core/transport/chttp2/frame.h
index 879ee036fac0f7018f01e35c2fcbbf5acf4a4fdc..560a6675af1be1a8db99cb07c563bc825e088942 100644
--- a/src/core/transport/chttp2/frame.h
+++ b/src/core/transport/chttp2/frame.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_FRAME_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_FRAME_H
 
 #include <grpc/support/port_platform.h>
 #include <grpc/support/slice.h>
@@ -66,4 +66,4 @@ typedef struct grpc_chttp2_transport_parsing grpc_chttp2_transport_parsing;
 #define GRPC_CHTTP2_DATA_FLAG_PADDED 8
 #define GRPC_CHTTP2_FLAG_HAS_PRIORITY 0x20
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_FRAME_H */
diff --git a/src/core/transport/chttp2/frame_data.h b/src/core/transport/chttp2/frame_data.h
index 936b7a25899cb6e73a0749cc8b61ed2d85e40b3d..92929d5c97302ec247fbfee4730e1d5353a78e5e 100644
--- a/src/core/transport/chttp2/frame_data.h
+++ b/src/core/transport/chttp2/frame_data.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_DATA_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_DATA_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_FRAME_DATA_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_FRAME_DATA_H
 
 /* Parser for GRPC streams embedded in DATA frames */
 
@@ -98,4 +98,4 @@ void grpc_chttp2_encode_data(uint32_t id, gpr_slice_buffer *inbuf,
                              uint32_t write_bytes, int is_eof,
                              gpr_slice_buffer *outbuf);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_DATA_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_FRAME_DATA_H */
diff --git a/src/core/transport/chttp2/frame_goaway.h b/src/core/transport/chttp2/frame_goaway.h
index e1a72b40134c1d6d6ce9d40edf13a920eca24502..616287e9ee5a98552c367a70b73199766e821c9c 100644
--- a/src/core/transport/chttp2/frame_goaway.h
+++ b/src/core/transport/chttp2/frame_goaway.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_GOAWAY_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_GOAWAY_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_FRAME_GOAWAY_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_FRAME_GOAWAY_H
 
 #include "src/core/iomgr/exec_ctx.h"
 #include "src/core/transport/chttp2/frame.h"
@@ -74,4 +74,4 @@ void grpc_chttp2_goaway_append(uint32_t last_stream_id, uint32_t error_code,
                                gpr_slice debug_data,
                                gpr_slice_buffer *slice_buffer);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_GOAWAY_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_FRAME_GOAWAY_H */
diff --git a/src/core/transport/chttp2/frame_ping.h b/src/core/transport/chttp2/frame_ping.h
index 16d7a726186a31108b7130d6e9c68b782f815f73..fc4dd7ac58f9d37d9557497c3799872274106c9b 100644
--- a/src/core/transport/chttp2/frame_ping.h
+++ b/src/core/transport/chttp2/frame_ping.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_PING_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_PING_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_FRAME_PING_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_FRAME_PING_H
 
 #include "src/core/iomgr/exec_ctx.h"
 #include <grpc/support/slice.h>
@@ -53,4 +53,4 @@ grpc_chttp2_parse_error grpc_chttp2_ping_parser_parse(
     grpc_chttp2_transport_parsing *transport_parsing,
     grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_PING_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_FRAME_PING_H */
diff --git a/src/core/transport/chttp2/frame_rst_stream.h b/src/core/transport/chttp2/frame_rst_stream.h
index 72ca654c3243b5e69720f4c571411e5911c73cc8..d563a22e24018d854cc9d94090ae38d4a51c9a5c 100644
--- a/src/core/transport/chttp2/frame_rst_stream.h
+++ b/src/core/transport/chttp2/frame_rst_stream.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_RST_STREAM_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_RST_STREAM_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_FRAME_RST_STREAM_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_FRAME_RST_STREAM_H
 
 #include <grpc/support/slice.h>
 #include "src/core/transport/chttp2/frame.h"
@@ -52,4 +52,4 @@ grpc_chttp2_parse_error grpc_chttp2_rst_stream_parser_parse(
     grpc_chttp2_transport_parsing *transport_parsing,
     grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_RST_STREAM_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_FRAME_RST_STREAM_H */
diff --git a/src/core/transport/chttp2/frame_settings.h b/src/core/transport/chttp2/frame_settings.h
index 3c918e3a2a90985489e2ad2910c7ff684455dcf6..e3c10d3cc5bb80a7db50fc4b571712241cdc3124 100644
--- a/src/core/transport/chttp2/frame_settings.h
+++ b/src/core/transport/chttp2/frame_settings.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_SETTINGS_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_SETTINGS_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_FRAME_SETTINGS_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_FRAME_SETTINGS_H
 
 #include <grpc/support/port_platform.h>
 #include <grpc/support/slice.h>
@@ -100,4 +100,4 @@ grpc_chttp2_parse_error grpc_chttp2_settings_parser_parse(
     grpc_chttp2_transport_parsing *transport_parsing,
     grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_SETTINGS_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_FRAME_SETTINGS_H */
diff --git a/src/core/transport/chttp2/frame_window_update.h b/src/core/transport/chttp2/frame_window_update.h
index 89d835c07979e6fbf566eb1a64d2f7c6ca329812..0b3712b09183a19cee5f6d6392cf96abd0b95bf9 100644
--- a/src/core/transport/chttp2/frame_window_update.h
+++ b/src/core/transport/chttp2/frame_window_update.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_WINDOW_UPDATE_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_WINDOW_UPDATE_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_FRAME_WINDOW_UPDATE_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_FRAME_WINDOW_UPDATE_H
 
 #include "src/core/iomgr/exec_ctx.h"
 #include <grpc/support/slice.h>
@@ -53,4 +53,4 @@ grpc_chttp2_parse_error grpc_chttp2_window_update_parser_parse(
     grpc_chttp2_transport_parsing *transport_parsing,
     grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_FRAME_WINDOW_UPDATE_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_FRAME_WINDOW_UPDATE_H */
diff --git a/src/core/transport/chttp2/hpack_encoder.h b/src/core/transport/chttp2/hpack_encoder.h
index 19b5cb72ae1579dd8a27086ec3e49b7ee1397623..90aaf867c51eb12627ac680cb827fa99fcefd97e 100644
--- a/src/core/transport/chttp2/hpack_encoder.h
+++ b/src/core/transport/chttp2/hpack_encoder.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HPACK_ENCODER_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HPACK_ENCODER_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_HPACK_ENCODER_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_HPACK_ENCODER_H
 
 #include "src/core/transport/chttp2/frame.h"
 #include "src/core/transport/metadata.h"
@@ -92,4 +92,4 @@ void grpc_chttp2_encode_header(grpc_chttp2_hpack_compressor *c, uint32_t id,
                                grpc_metadata_batch *metadata, int is_eof,
                                gpr_slice_buffer *outbuf);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HPACK_ENCODER_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_HPACK_ENCODER_H */
diff --git a/src/core/transport/chttp2/hpack_parser.h b/src/core/transport/chttp2/hpack_parser.h
index 1ad0c64fb9cae281e664243fe7d1686faa105f36..6a6d136da25b606cca2ded25cfb273bb57845221 100644
--- a/src/core/transport/chttp2/hpack_parser.h
+++ b/src/core/transport/chttp2/hpack_parser.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HPACK_PARSER_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HPACK_PARSER_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_HPACK_PARSER_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_HPACK_PARSER_H
 
 #include <stddef.h>
 
@@ -113,4 +113,4 @@ grpc_chttp2_parse_error grpc_chttp2_header_parser_parse(
     grpc_chttp2_transport_parsing *transport_parsing,
     grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HPACK_PARSER_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_HPACK_PARSER_H */
diff --git a/src/core/transport/chttp2/hpack_table.h b/src/core/transport/chttp2/hpack_table.h
index e7431255fc7fbbd39240907e46a42068dddb9572..6e1b5e66b5d06663695077617ac346484cba9892 100644
--- a/src/core/transport/chttp2/hpack_table.h
+++ b/src/core/transport/chttp2/hpack_table.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HPACK_TABLE_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HPACK_TABLE_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_HPACK_TABLE_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_HPACK_TABLE_H
 
 #include "src/core/transport/metadata.h"
 #include <grpc/support/port_platform.h>
@@ -105,4 +105,4 @@ typedef struct {
 grpc_chttp2_hptbl_find_result grpc_chttp2_hptbl_find(
     const grpc_chttp2_hptbl *tbl, grpc_mdelem *md);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HPACK_TABLE_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_HPACK_TABLE_H */
diff --git a/src/core/transport/chttp2/http2_errors.h b/src/core/transport/chttp2/http2_errors.h
index a4f309e0565d40ed251f2c799ccb4d1b02d5ecb4..4290df3d894753f984797d1335214c91c580bc21 100644
--- a/src/core/transport/chttp2/http2_errors.h
+++ b/src/core/transport/chttp2/http2_errors.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HTTP2_ERRORS_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HTTP2_ERRORS_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_HTTP2_ERRORS_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_HTTP2_ERRORS_H
 
 /* error codes for RST_STREAM from http2 draft 14 section 7 */
 typedef enum {
@@ -53,4 +53,4 @@ typedef enum {
   GRPC_CHTTP2__ERROR_DO_NOT_USE = -1
 } grpc_chttp2_error_code;
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HTTP2_ERRORS_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_HTTP2_ERRORS_H */
diff --git a/src/core/transport/chttp2/huffsyms.h b/src/core/transport/chttp2/huffsyms.h
index a3cdba8235a1a75820a41050391e1fba87a7cb79..9c4f09dcf6e894442036e3679c7d5b89ee4789a5 100644
--- a/src/core/transport/chttp2/huffsyms.h
+++ b/src/core/transport/chttp2/huffsyms.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HUFFSYMS_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HUFFSYMS_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_HUFFSYMS_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_HUFFSYMS_H
 
 /* HPACK static huffman table */
 
@@ -45,4 +45,4 @@ typedef struct {
 
 extern const grpc_chttp2_huffsym grpc_chttp2_huffsyms[GRPC_CHTTP2_NUM_HUFFSYMS];
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_HUFFSYMS_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_HUFFSYMS_H */
diff --git a/src/core/transport/chttp2/incoming_metadata.h b/src/core/transport/chttp2/incoming_metadata.h
index ea74cfc64b2a7cd57cb977dd477341b8fea886c8..52454f348c8f1bedfa8c6879d11302e9a867fdda 100644
--- a/src/core/transport/chttp2/incoming_metadata.h
+++ b/src/core/transport/chttp2/incoming_metadata.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHTTP2_INCOMING_METADATA_H
-#define GRPC_INTERNAL_CORE_CHTTP2_INCOMING_METADATA_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_INCOMING_METADATA_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_INCOMING_METADATA_H
 
 #include "src/core/transport/transport.h"
 
@@ -57,4 +57,4 @@ void grpc_chttp2_incoming_metadata_buffer_add(
 void grpc_chttp2_incoming_metadata_buffer_set_deadline(
     grpc_chttp2_incoming_metadata_buffer *buffer, gpr_timespec deadline);
 
-#endif /* GRPC_INTERNAL_CORE_CHTTP2_INCOMING_METADATA_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_INCOMING_METADATA_H */
diff --git a/src/core/transport/chttp2/internal.h b/src/core/transport/chttp2/internal.h
index b720d1ab3e5a64cdb369ac83fcc375f9bff56c4d..0690cb37cdec0cae13f9b2264bd558a48df30ad2 100644
--- a/src/core/transport/chttp2/internal.h
+++ b/src/core/transport/chttp2/internal.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_CHTTP2_INTERNAL_H
-#define GRPC_INTERNAL_CORE_CHTTP2_INTERNAL_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_INTERNAL_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_INTERNAL_H
 
 #include <assert.h>
 #include <stdbool.h>
@@ -777,4 +777,4 @@ void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx,
 void grpc_chttp2_become_writable(grpc_chttp2_transport_global *transport_global,
                                  grpc_chttp2_stream_global *stream_global);
 
-#endif
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_INTERNAL_H */
diff --git a/src/core/transport/chttp2/status_conversion.h b/src/core/transport/chttp2/status_conversion.h
index 0ec5b560b8ed0df1f4010abd79d876d91c260eea..c6e066bb5da69888ef3a05542bacdf9b94efa78b 100644
--- a/src/core/transport/chttp2/status_conversion.h
+++ b/src/core/transport/chttp2/status_conversion.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_STATUS_CONVERSION_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_STATUS_CONVERSION_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_STATUS_CONVERSION_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_STATUS_CONVERSION_H
 
 #include <grpc/grpc.h>
 #include "src/core/transport/chttp2/http2_errors.h"
@@ -47,4 +47,4 @@ grpc_status_code grpc_chttp2_http2_error_to_grpc_status(
 grpc_status_code grpc_chttp2_http2_status_to_grpc_status(int status);
 int grpc_chttp2_grpc_status_to_http2_status(grpc_status_code status);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_STATUS_CONVERSION_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_STATUS_CONVERSION_H */
diff --git a/src/core/transport/chttp2/stream_map.h b/src/core/transport/chttp2/stream_map.h
index 7a0e45fab2ca14c4757350d3d3ddc13b48fd88cc..957a58a4f27d9dec7ced5b0476c468214f2d24cc 100644
--- a/src/core/transport/chttp2/stream_map.h
+++ b/src/core/transport/chttp2/stream_map.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_STREAM_MAP_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_STREAM_MAP_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_STREAM_MAP_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_STREAM_MAP_H
 
 #include <grpc/support/port_platform.h>
 
@@ -81,4 +81,4 @@ void grpc_chttp2_stream_map_for_each(grpc_chttp2_stream_map *map,
                                                void *value),
                                      void *user_data);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_STREAM_MAP_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_STREAM_MAP_H */
diff --git a/src/core/transport/chttp2/timeout_encoding.h b/src/core/transport/chttp2/timeout_encoding.h
index 9d8756e799d3d8112cfff1c99cf47b2072403600..81bae8e9363a8b28f778e12db39453a339ee6876 100644
--- a/src/core/transport/chttp2/timeout_encoding.h
+++ b/src/core/transport/chttp2/timeout_encoding.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_TIMEOUT_ENCODING_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_TIMEOUT_ENCODING_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_TIMEOUT_ENCODING_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_TIMEOUT_ENCODING_H
 
 #include "src/core/support/string.h"
 #include <grpc/support/time.h>
@@ -44,4 +44,4 @@
 void grpc_chttp2_encode_timeout(gpr_timespec timeout, char *buffer);
 int grpc_chttp2_decode_timeout(const char *buffer, gpr_timespec *timeout);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_TIMEOUT_ENCODING_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_TIMEOUT_ENCODING_H */
diff --git a/src/core/transport/chttp2/varint.h b/src/core/transport/chttp2/varint.h
index 2d92b6693e9c87f28dbd506a2da78e8606edfd22..7ab9d22ab52de5ac73eb4b6fc4393f12796ced6b 100644
--- a/src/core/transport/chttp2/varint.h
+++ b/src/core/transport/chttp2/varint.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_VARINT_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_VARINT_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_VARINT_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_VARINT_H
 
 #include <grpc/support/port_platform.h>
 
@@ -72,4 +72,4 @@ void grpc_chttp2_hpack_write_varint_tail(uint32_t tail_value, uint8_t* target,
     }                                                                         \
   } while (0)
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_VARINT_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_VARINT_H */
diff --git a/src/core/transport/chttp2_transport.h b/src/core/transport/chttp2_transport.h
index 95520501edde98b3272d9a6e23f267b4402a69be..9a6cf0ed359607bd5cf083db2e9f5ac0ccb955e5 100644
--- a/src/core/transport/chttp2_transport.h
+++ b/src/core/transport/chttp2_transport.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_TRANSPORT_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_TRANSPORT_H
+#ifndef GRPC_CORE_TRANSPORT_CHTTP2_TRANSPORT_H
+#define GRPC_CORE_TRANSPORT_CHTTP2_TRANSPORT_H
 
 #include "src/core/iomgr/endpoint.h"
 #include "src/core/transport/transport.h"
@@ -48,4 +48,4 @@ void grpc_chttp2_transport_start_reading(grpc_exec_ctx *exec_ctx,
                                          grpc_transport *transport,
                                          gpr_slice *slices, size_t nslices);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_TRANSPORT_H */
+#endif /* GRPC_CORE_TRANSPORT_CHTTP2_TRANSPORT_H */
diff --git a/src/core/transport/connectivity_state.h b/src/core/transport/connectivity_state.h
index a4eb6652e551b815d28b51e29d11d93472088d73..b4a3ce924d41ce955cc1d321f52965deb2de5972 100644
--- a/src/core/transport/connectivity_state.h
+++ b/src/core/transport/connectivity_state.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_CONNECTIVITY_STATE_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_CONNECTIVITY_STATE_H
+#ifndef GRPC_CORE_TRANSPORT_CONNECTIVITY_STATE_H
+#define GRPC_CORE_TRANSPORT_CONNECTIVITY_STATE_H
 
 #include <grpc/grpc.h>
 #include "src/core/iomgr/exec_ctx.h"
@@ -82,4 +82,4 @@ int grpc_connectivity_state_notify_on_state_change(
     grpc_exec_ctx *exec_ctx, grpc_connectivity_state_tracker *tracker,
     grpc_connectivity_state *current, grpc_closure *notify);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_CONNECTIVITY_STATE_H */
+#endif /* GRPC_CORE_TRANSPORT_CONNECTIVITY_STATE_H */
diff --git a/src/core/transport/metadata.h b/src/core/transport/metadata.h
index 8742846be7e6250d7987b196bb7e4e2b500e6055..5ab397848cc237ffad4de1323499c10513964972 100644
--- a/src/core/transport/metadata.h
+++ b/src/core/transport/metadata.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_METADATA_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_METADATA_H
+#ifndef GRPC_CORE_TRANSPORT_METADATA_H
+#define GRPC_CORE_TRANSPORT_METADATA_H
 
 #include <grpc/support/slice.h>
 #include <grpc/support/useful.h>
@@ -153,4 +153,4 @@ int grpc_mdstr_is_bin_suffixed(grpc_mdstr *s);
 void grpc_mdctx_global_init(void);
 void grpc_mdctx_global_shutdown(void);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_METADATA_H */
+#endif /* GRPC_CORE_TRANSPORT_METADATA_H */
diff --git a/src/core/transport/metadata_batch.h b/src/core/transport/metadata_batch.h
index 1b0d1fda3e220589cc8271eb6867a2aaf8c46a62..9337b28328e9b8a8789c11d6cd6cc659564a4af8 100644
--- a/src/core/transport/metadata_batch.h
+++ b/src/core/transport/metadata_batch.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_STREAM_OP_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_STREAM_OP_H
+#ifndef GRPC_CORE_TRANSPORT_METADATA_BATCH_H
+#define GRPC_CORE_TRANSPORT_METADATA_BATCH_H
 
 #include <grpc/grpc.h>
 #include <grpc/support/port_platform.h>
@@ -122,4 +122,4 @@ void grpc_metadata_batch_assert_ok(grpc_metadata_batch *comd);
   } while (0)
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_STREAM_OP_H */
+#endif /* GRPC_CORE_TRANSPORT_METADATA_BATCH_H */
diff --git a/src/core/transport/static_metadata.h b/src/core/transport/static_metadata.h
index ef72b802b51bbcbc35d0e888c886b2ee96efe955..85442f81078720ab93b0d3a1c95e509855db4ae5 100644
--- a/src/core/transport/static_metadata.h
+++ b/src/core/transport/static_metadata.h
@@ -43,8 +43,8 @@
  * explanation of what's going on.
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_STATIC_METADATA_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_STATIC_METADATA_H
+#ifndef GRPC_CORE_TRANSPORT_STATIC_METADATA_H
+#define GRPC_CORE_TRANSPORT_STATIC_METADATA_H
 
 #include "src/core/transport/metadata.h"
 
@@ -405,4 +405,4 @@ extern const char *const grpc_static_metadata_strings[GRPC_STATIC_MDSTR_COUNT];
 extern const uint8_t grpc_static_accept_encoding_metadata[8];
 #define GRPC_MDELEM_ACCEPT_ENCODING_FOR_ALGORITHMS(algs) \
   (&grpc_static_mdelem_table[grpc_static_accept_encoding_metadata[(algs)]])
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_STATIC_METADATA_H */
+#endif /* GRPC_CORE_TRANSPORT_STATIC_METADATA_H */
diff --git a/src/core/transport/transport.h b/src/core/transport/transport.h
index ed6e121c9cbb685e4b7e109a7f92110320f9c424..0f068dcb38f0951d34064293b3460306d93d954a 100644
--- a/src/core/transport/transport.h
+++ b/src/core/transport/transport.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_TRANSPORT_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_TRANSPORT_H
+#ifndef GRPC_CORE_TRANSPORT_TRANSPORT_H
+#define GRPC_CORE_TRANSPORT_TRANSPORT_H
 
 #include <stddef.h>
 
@@ -239,4 +239,4 @@ void grpc_transport_destroy(grpc_exec_ctx *exec_ctx, grpc_transport *transport);
 char *grpc_transport_get_peer(grpc_exec_ctx *exec_ctx,
                               grpc_transport *transport);
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_TRANSPORT_H */
+#endif /* GRPC_CORE_TRANSPORT_TRANSPORT_H */
diff --git a/src/core/transport/transport_impl.h b/src/core/transport/transport_impl.h
index 40bfb4b13ac14a36e6c936630cc0fcc40b3be8d9..fe9a653f7f075272a06e89615f6a9ad7b775a851 100644
--- a/src/core/transport/transport_impl.h
+++ b/src/core/transport/transport_impl.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TRANSPORT_TRANSPORT_IMPL_H
-#define GRPC_INTERNAL_CORE_TRANSPORT_TRANSPORT_IMPL_H
+#ifndef GRPC_CORE_TRANSPORT_TRANSPORT_IMPL_H
+#define GRPC_CORE_TRANSPORT_TRANSPORT_IMPL_H
 
 #include "src/core/transport/transport.h"
 
@@ -75,4 +75,4 @@ struct grpc_transport {
   const grpc_transport_vtable *vtable;
 };
 
-#endif /* GRPC_INTERNAL_CORE_TRANSPORT_TRANSPORT_IMPL_H */
+#endif /* GRPC_CORE_TRANSPORT_TRANSPORT_IMPL_H */
diff --git a/src/core/tsi/fake_transport_security.h b/src/core/tsi/fake_transport_security.h
index fe295aa53607ca63c8d2f060d5dfb8bb0a3da613..6b8e5962905740914934fb3ed4ec7ee7dc8cccc8 100644
--- a/src/core/tsi/fake_transport_security.h
+++ b/src/core/tsi/fake_transport_security.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TSI_FAKE_TRANSPORT_SECURITY_H
-#define GRPC_INTERNAL_CORE_TSI_FAKE_TRANSPORT_SECURITY_H
+#ifndef GRPC_CORE_TSI_FAKE_TRANSPORT_SECURITY_H
+#define GRPC_CORE_TSI_FAKE_TRANSPORT_SECURITY_H
 
 #include "src/core/tsi/transport_security_interface.h"
 
@@ -58,4 +58,4 @@ tsi_frame_protector *tsi_create_fake_protector(
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_TSI_FAKE_TRANSPORT_SECURITY_H */
+#endif /* GRPC_CORE_TSI_FAKE_TRANSPORT_SECURITY_H */
diff --git a/src/core/tsi/ssl_transport_security.h b/src/core/tsi/ssl_transport_security.h
index 32bb067f0bf499f566b5058312439eb90d27256e..612f5c64cc12bba4e76bac7ffd042ece909622de 100644
--- a/src/core/tsi/ssl_transport_security.h
+++ b/src/core/tsi/ssl_transport_security.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TSI_SSL_TRANSPORT_SECURITY_H
-#define GRPC_INTERNAL_CORE_TSI_SSL_TRANSPORT_SECURITY_H
+#ifndef GRPC_CORE_TSI_SSL_TRANSPORT_SECURITY_H
+#define GRPC_CORE_TSI_SSL_TRANSPORT_SECURITY_H
 
 #include "src/core/tsi/transport_security_interface.h"
 
@@ -171,4 +171,4 @@ int tsi_ssl_peer_matches_name(const tsi_peer *peer, const char *name);
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_TSI_SSL_TRANSPORT_SECURITY_H */
+#endif /* GRPC_CORE_TSI_SSL_TRANSPORT_SECURITY_H */
diff --git a/src/core/tsi/ssl_types.h b/src/core/tsi/ssl_types.h
index 0d0225e9c7ba83cd96010693f4612cb68e7bac7f..6ea85fe6d4730844bd4873aadccbbae2d254136a 100644
--- a/src/core/tsi/ssl_types.h
+++ b/src/core/tsi/ssl_types.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TSI_SSL_TYPES_H
-#define GRPC_INTERNAL_CORE_TSI_SSL_TYPES_H
+#ifndef GRPC_CORE_TSI_SSL_TYPES_H
+#define GRPC_CORE_TSI_SSL_TYPES_H
 
 /* A collection of macros to cast between various integer types that are
  * used differently between BoringSSL and OpenSSL:
@@ -52,4 +52,4 @@
 #define TSI_SIZE_AS_SIZE(x) ((int)(x))
 #endif
 
-#endif
+#endif /* GRPC_CORE_TSI_SSL_TYPES_H */
diff --git a/src/core/tsi/transport_security.h b/src/core/tsi/transport_security.h
index 4077737473ac5b34468fa75e109bb94d4ad2b691..ecc037193ba6ef4c2593dd5726d1370096b89edd 100644
--- a/src/core/tsi/transport_security.h
+++ b/src/core/tsi/transport_security.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TSI_TRANSPORT_SECURITY_H
-#define GRPC_INTERNAL_CORE_TSI_TRANSPORT_SECURITY_H
+#ifndef GRPC_CORE_TSI_TRANSPORT_SECURITY_H
+#define GRPC_CORE_TSI_TRANSPORT_SECURITY_H
 
 #include "src/core/tsi/transport_security_interface.h"
 
@@ -108,4 +108,4 @@ char *tsi_strdup(const char *src); /* Sadly, no strdup in C89. */
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_TSI_TRANSPORT_SECURITY_H */
+#endif /* GRPC_CORE_TSI_TRANSPORT_SECURITY_H */
diff --git a/src/core/tsi/transport_security_interface.h b/src/core/tsi/transport_security_interface.h
index 69ee17ae917924c88448815a60c86fb8f5bf37d4..08501802f55d036b3e9ff8ef731cd6a14d8166e1 100644
--- a/src/core/tsi/transport_security_interface.h
+++ b/src/core/tsi/transport_security_interface.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_TSI_TRANSPORT_SECURITY_INTERFACE_H
-#define GRPC_INTERNAL_CORE_TSI_TRANSPORT_SECURITY_INTERFACE_H
+#ifndef GRPC_CORE_TSI_TRANSPORT_SECURITY_INTERFACE_H
+#define GRPC_CORE_TSI_TRANSPORT_SECURITY_INTERFACE_H
 
 #include <stdint.h>
 #include <stdlib.h>
@@ -341,4 +341,4 @@ void tsi_handshaker_destroy(tsi_handshaker *self);
 }
 #endif
 
-#endif /* GRPC_INTERNAL_CORE_TSI_TRANSPORT_SECURITY_INTERFACE_H */
+#endif /* GRPC_CORE_TSI_TRANSPORT_SECURITY_INTERFACE_H */
diff --git a/src/python/grpcio/commands.py b/src/python/grpcio/commands.py
index c1f444f6f1f07911aa1c8d50acd84d3b8bd3e354..1d435474198521a12f45d2d6ca500566608776fb 100644
--- a/src/python/grpcio/commands.py
+++ b/src/python/grpcio/commands.py
@@ -288,15 +288,9 @@ class TestLite(setuptools.Command):
       sys.exit('Test failure')
 
   def _add_eggs_to_path(self):
-    """Adds all egg files under .eggs to sys.path"""
-    # TODO(jtattemusch): there has to be a cleaner way to do this
-    import pkg_resources
-    eggs_dir = os.path.join(PYTHON_STEM, '../../../.eggs')
-    eggs = [os.path.join(eggs_dir, filename)
-            for filename in os.listdir(eggs_dir)
-            if filename.endswith('.egg')]
-    for egg in eggs:
-      sys.path.insert(0, pkg_resources.normalize_path(egg))
+    """Fetch install and test requirements"""
+    self.distribution.fetch_build_eggs(self.distribution.install_requires)
+    self.distribution.fetch_build_eggs(self.distribution.tests_require)
 
 
 class RunInterop(test.test):
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index a543791f5ce47c83b75b36416c70e644047e80d4..31e16e04912bb623b93d915910fa6435678972ce 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -34,6 +34,7 @@ CORE_SOURCE_FILES = [
   'src/core/profiling/stap_timers.c',
   'src/core/support/alloc.c',
   'src/core/support/avl.c',
+  'src/core/support/backoff.c',
   'src/core/support/cmdline.c',
   'src/core/support/cpu_iphone.c',
   'src/core/support/cpu_linux.c',
diff --git a/test/core/client_config/lb_policies_test.c b/test/core/client_config/lb_policies_test.c
index cb99b3da3e767efdf72d63278e11e1fcbd0eabcd..1ea0c423c189a5500261c673f61e98f052782dec 100644
--- a/test/core/client_config/lb_policies_test.c
+++ b/test/core/client_config/lb_policies_test.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -52,6 +52,8 @@
 #include "test/core/util/port.h"
 #include "test/core/util/test_config.h"
 
+#define RETRY_TIMEOUT 300
+
 typedef struct servers_fixture {
   size_t num_servers;
   grpc_server **servers;
@@ -303,8 +305,8 @@ static int *perform_request(servers_fixture *f, grpc_channel *client,
 
     s_idx = -1;
     while ((ev = grpc_completion_queue_next(
-                f->cq, GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1), NULL)).type !=
-           GRPC_QUEUE_TIMEOUT) {
+                f->cq, GRPC_TIMEOUT_MILLIS_TO_DEADLINE(10 * RETRY_TIMEOUT),
+                NULL)).type != GRPC_QUEUE_TIMEOUT) {
       GPR_ASSERT(ev.type == GRPC_OP_COMPLETE);
       read_tag = ((int)(intptr_t)ev.tag);
       gpr_log(GPR_DEBUG, "EVENT: success:%d, type:%d, tag:%d iter:%d",
@@ -376,9 +378,9 @@ static int *perform_request(servers_fixture *f, grpc_channel *client,
       }
     }
 
-    GPR_ASSERT(grpc_completion_queue_next(f->cq,
-                                          GRPC_TIMEOUT_MILLIS_TO_DEADLINE(200),
-                                          NULL).type == GRPC_QUEUE_TIMEOUT);
+    GPR_ASSERT(grpc_completion_queue_next(
+                   f->cq, GRPC_TIMEOUT_MILLIS_TO_DEADLINE(2 * RETRY_TIMEOUT),
+                   NULL).type == GRPC_QUEUE_TIMEOUT);
 
     grpc_metadata_array_destroy(&rdata->initial_metadata_recv);
     grpc_metadata_array_destroy(&rdata->trailing_metadata_recv);
@@ -506,7 +508,7 @@ void run_spec(const test_spec *spec) {
 
   arg.type = GRPC_ARG_INTEGER;
   arg.key = "grpc.testing.fixed_reconnect_backoff";
-  arg.value.integer = 100;
+  arg.value.integer = RETRY_TIMEOUT;
   args.num_args = 1;
   args.args = &arg;
 
@@ -542,7 +544,7 @@ static grpc_channel *create_client(const servers_fixture *f) {
 
   arg.type = GRPC_ARG_INTEGER;
   arg.key = "grpc.testing.fixed_reconnect_backoff";
-  arg.value.integer = 100;
+  arg.value.integer = RETRY_TIMEOUT;
   args.num_args = 1;
   args.args = &arg;
 
diff --git a/test/core/support/backoff_test.c b/test/core/support/backoff_test.c
new file mode 100644
index 0000000000000000000000000000000000000000..870b60b2d5aefae09398dcb22c820d21b76da711
--- /dev/null
+++ b/test/core/support/backoff_test.c
@@ -0,0 +1,107 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/support/backoff.h"
+
+#include <grpc/support/log.h>
+
+#include "test/core/util/test_config.h"
+
+static void test_constant_backoff(void) {
+  gpr_backoff backoff;
+  gpr_backoff_init(&backoff, 1.0, 0.0, 1000, 1000);
+
+  gpr_timespec now = gpr_time_0(GPR_TIMESPAN);
+  gpr_timespec next = gpr_backoff_begin(&backoff, now);
+  GPR_ASSERT(gpr_time_to_millis(gpr_time_sub(next, now)) == 1000);
+  for (int i = 0; i < 10000; i++) {
+    next = gpr_backoff_step(&backoff, now);
+    GPR_ASSERT(gpr_time_to_millis(gpr_time_sub(next, now)) == 1000);
+    now = next;
+  }
+}
+
+static void test_no_jitter_backoff(void) {
+  gpr_backoff backoff;
+  gpr_backoff_init(&backoff, 2.0, 0.0, 1, 513);
+
+  gpr_timespec now = gpr_time_0(GPR_TIMESPAN);
+  gpr_timespec next = gpr_backoff_begin(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(3, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(7, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(15, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(31, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(63, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(127, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(255, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(511, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1023, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1536, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(2049, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(2562, GPR_TIMESPAN), next) == 0);
+}
+
+int main(int argc, char **argv) {
+  grpc_test_init(argc, argv);
+  gpr_time_init();
+
+  test_constant_backoff();
+  test_no_jitter_backoff();
+
+  return 0;
+}
diff --git a/tools/distrib/check_include_guards.py b/tools/distrib/check_include_guards.py
new file mode 100755
index 0000000000000000000000000000000000000000..977f40e0b3ec873b1a84849471ae194d81b63f59
--- /dev/null
+++ b/tools/distrib/check_include_guards.py
@@ -0,0 +1,197 @@
+#!/usr/bin/env python2.7
+
+# Copyright 2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import argparse
+import os
+import re
+import sys
+import subprocess
+
+
+def build_valid_guard(fpath):
+  prefix = 'GRPC_' if not fpath.startswith('include/') else ''
+  return prefix + '_'.join(fpath.replace('++', 'XX').replace('.', '_').upper().split('/')[1:])
+
+
+def load(fpath):
+  with open(fpath, 'r') as f:
+    return f.read()
+
+
+def save(fpath, contents):
+  with open(fpath, 'w') as f:
+    f.write(contents)
+
+
+class GuardValidator(object):
+  def __init__(self):
+    self.ifndef_re = re.compile(r'#ifndef ([A-Z][A-Z_1-9]*)')
+    self.define_re = re.compile(r'#define ([A-Z][A-Z_1-9]*)')
+    self.endif_c_re = re.compile(r'#endif /\* ([A-Z][A-Z_1-9]*) \*/')
+    self.endif_cpp_re = re.compile(r'#endif  // ([A-Z][A-Z_1-9]*)')
+    self.failed = False
+
+  def fail(self, fpath, regexp, fcontents, match_txt, correct, fix):
+    cpp_header = 'grpc++' in fpath
+    self.failed = True
+    invalid_guards_msg_template = (
+        '{0}: Missing preprocessor guards (RE {1}). '
+        'Please wrap your code around the following guards:\n'
+        '#ifndef {2}\n'
+        '#define {2}\n'
+        '...\n'
+        '... epic code ...\n'
+        '...\n') + ('#endif  // {2}' if cpp_header else '#endif /* {2} */')
+    if not match_txt:
+      print invalid_guards_msg_template.format(fpath, regexp.pattern,
+                                               build_valid_guard(fpath))
+      return fcontents
+
+    print ('{}: Wrong preprocessor guards (RE {}):'
+           '\n\tFound {}, expected {}').format(
+        fpath, regexp.pattern, match_txt, correct)
+    if fix:
+      print 'Fixing {}...\n'.format(fpath)
+      fixed_fcontents = re.sub(match_txt, correct, fcontents)
+      if fixed_fcontents:
+        self.failed = False
+      return fixed_fcontents
+    else:
+      print
+    return fcontents
+
+  def check(self, fpath, fix):
+    cpp_header = 'grpc++' in fpath
+    valid_guard = build_valid_guard(fpath)
+
+    fcontents = load(fpath)
+
+    match = self.ifndef_re.search(fcontents)
+    if match.lastindex is None:
+      # No ifndef. Request manual addition with hints
+      self.fail(fpath, match.re, match.string, '', '', False)
+      return False  # failed
+
+    # Does the guard end with a '_H'?
+    running_guard = match.group(1)
+    if not running_guard.endswith('_H'):
+      fcontents = self.fail(fpath, match.re, match.string, match.group(1),
+                            valid_guard, fix)
+      if fix: save(fpath, fcontents)
+
+    # Is it the expected one based on the file path?
+    if running_guard != valid_guard:
+      fcontents = self.fail(fpath, match.re, match.string, match.group(1),
+                            valid_guard, fix)
+      if fix: save(fpath, fcontents)
+
+    # Is there a #define? Is it the same as the #ifndef one?
+    match = self.define_re.search(fcontents)
+    if match.lastindex is None:
+      # No define. Request manual addition with hints
+      self.fail(fpath, match.re, match.string, '', '', False)
+      return False  # failed
+
+    # Is the #define guard the same as the #ifndef guard?
+    if match.group(1) != running_guard:
+      fcontents = self.fail(fpath, match.re, match.string, match.group(1),
+                            valid_guard, fix)
+      if fix: save(fpath, fcontents)
+
+    # Is there a properly commented #endif?
+    endif_re = self.endif_cpp_re if cpp_header else self.endif_c_re
+    flines = fcontents.rstrip().splitlines()
+    match = endif_re.search(flines[-1])
+    if not match:
+      # No endif. Check if we have the last line as just '#endif' and if so
+      # replace it with a properly commented one.
+      if flines[-1] == '#endif':
+        flines[-1] = ('#endif' +
+                      ('  // {}\n'.format(valid_guard) if cpp_header
+                       else ' /* {} */\n'.format(valid_guard)))
+        if fix:
+            fcontents = '\n'.join(flines)
+            save(fpath, fcontents)
+      else:
+        # something else is wrong, bail out
+        self.fail(fpath, endif_re, flines[-1], '', '', False)
+    elif match.group(1) != running_guard:
+      # Is the #endif guard the same as the #ifndef and #define guards?
+      fcontents = self.fail(fpath, endif_re, fcontents, match.group(1),
+                            valid_guard, fix)
+      if fix: save(fpath, fcontents)
+
+    return not self.failed  # Did the check succeed? (ie, not failed)
+
+# find our home
+ROOT = os.path.abspath(
+    os.path.join(os.path.dirname(sys.argv[0]), '../..'))
+os.chdir(ROOT)
+
+# parse command line
+argp = argparse.ArgumentParser(description='include guard checker')
+argp.add_argument('-f', '--fix',
+                  default=False,
+                  action='store_true');
+argp.add_argument('--precommit',
+                  default=False,
+                  action='store_true')
+args = argp.parse_args()
+
+KNOWN_BAD = set([
+    'src/core/proto/grpc/lb/v0/load_balancer.pb.h',
+])
+
+
+grep_filter = r"grep -E '^(include|src/core)/.*\.h$'"
+if args.precommit:
+  git_command = 'git diff --name-only HEAD'
+else:
+  git_command = 'git ls-tree -r --name-only -r HEAD'
+
+FILE_LIST_COMMAND = ' | '.join((git_command, grep_filter))
+
+# scan files
+ok = True
+filename_list = []
+try:
+  filename_list = subprocess.check_output(FILE_LIST_COMMAND,
+                                          shell=True).splitlines()
+except subprocess.CalledProcessError:
+  sys.exit(0)
+
+validator = GuardValidator()
+
+for filename in filename_list:
+  if filename in KNOWN_BAD: continue
+  ok = validator.check(filename, args.fix)
+
+sys.exit(0 if ok else 1)
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index 71b7af2a2270bfa4dd91a3fe1a9811f1972da4a3..a06d4ecb4268bcc26fdd94553ff6b47ae75ef484 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -1112,6 +1112,7 @@ include/grpc/impl/codegen/sync_posix.h \
 include/grpc/impl/codegen/sync_win32.h \
 include/grpc/impl/codegen/time.h \
 src/core/profiling/timers.h \
+src/core/support/backoff.h \
 src/core/support/block_annotate.h \
 src/core/support/env.h \
 src/core/support/load_file.h \
@@ -1126,6 +1127,7 @@ src/core/profiling/basic_timers.c \
 src/core/profiling/stap_timers.c \
 src/core/support/alloc.c \
 src/core/support/avl.c \
+src/core/support/backoff.c \
 src/core/support/cmdline.c \
 src/core/support/cpu_iphone.c \
 src/core/support/cpu_linux.c \
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index f81909ab88f12ac6000c6a4e24f2a51cd306fbf6..dc11c0bd51deb738e5c1de02e62022f8ee92fc84 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -80,7 +80,7 @@ class Config(object):
     self.timeout_multiplier = timeout_multiplier
 
   def job_spec(self, cmdline, hash_targets, timeout_seconds=5*60,
-               shortname=None, environ={}, cpu_cost=1.0):
+               shortname=None, environ={}, cpu_cost=1.0, flaky=False):
     """Construct a jobset.JobSpec for a test under this config
 
        Args:
@@ -102,7 +102,7 @@ class Config(object):
                           timeout_seconds=(self.timeout_multiplier * timeout_seconds if timeout_seconds else None),
                           hash_targets=hash_targets
                               if self.allow_hashing else None,
-                          flake_retries=5 if args.allow_flakes else 0,
+                          flake_retries=5 if flaky or args.allow_flakes else 0,
                           timeout_retries=3 if args.allow_flakes else 0)
 
 
@@ -189,6 +189,7 @@ class CLanguage(object):
           out.append(self.config.job_spec(cmdline, [binary],
                                           shortname=' '.join(cmdline),
                                           cpu_cost=target['cpu_cost'],
+                                          flaky=target.get('flaky', False),
                                           environ={'GRPC_DEFAULT_SSL_ROOTS_FILE_PATH':
                                                    _ROOT + '/src/core/tsi/test_creds/ca.pem'}))
       elif self.args.regex == '.*' or self.platform == 'windows':
@@ -882,7 +883,7 @@ if args.use_docker:
       sys.exit(1)
   else:
     dockerfile_dir = next(iter(dockerfile_dirs))
-    
+
   child_argv = [ arg for arg in sys.argv if not arg == '--use_docker' ]
   run_tests_cmd = 'python tools/run_tests/run_tests.py %s' % ' '.join(child_argv[1:])
 
diff --git a/tools/run_tests/sanity/sanity_tests.yaml b/tools/run_tests/sanity/sanity_tests.yaml
index 3840f4d8df6a3a54b7bef81008fba93290cb78f7..f155c8da45af540aacb470be561ab9d4df130911 100644
--- a/tools/run_tests/sanity/sanity_tests.yaml
+++ b/tools/run_tests/sanity/sanity_tests.yaml
@@ -8,3 +8,4 @@
 - script: tools/distrib/clang_format_code.sh
 - script: tools/distrib/check_trailing_newlines.sh
 - script: tools/distrib/check_nanopb_output.sh
+- script: tools/distrib/check_include_guards.py
diff --git a/tools/run_tests/sources_and_headers.json b/tools/run_tests/sources_and_headers.json
index ae227005ad46350fe9f6561320d4bb23c267f86a..0f54d5625beb9baa83affd4f440a3bfa11889e42 100644
--- a/tools/run_tests/sources_and_headers.json
+++ b/tools/run_tests/sources_and_headers.json
@@ -404,6 +404,20 @@
     "third_party": false, 
     "type": "target"
   }, 
+  {
+    "deps": [
+      "gpr", 
+      "gpr_test_util"
+    ], 
+    "headers": [], 
+    "language": "c", 
+    "name": "gpr_backoff_test", 
+    "src": [
+      "test/core/support/backoff_test.c"
+    ], 
+    "third_party": false, 
+    "type": "target"
+  }, 
   {
     "deps": [
       "gpr", 
@@ -3746,6 +3760,7 @@
       "include/grpc/support/tls_pthread.h", 
       "include/grpc/support/useful.h", 
       "src/core/profiling/timers.h", 
+      "src/core/support/backoff.h", 
       "src/core/support/block_annotate.h", 
       "src/core/support/env.h", 
       "src/core/support/load_file.h", 
@@ -3807,6 +3822,8 @@
       "src/core/profiling/timers.h", 
       "src/core/support/alloc.c", 
       "src/core/support/avl.c", 
+      "src/core/support/backoff.c", 
+      "src/core/support/backoff.h", 
       "src/core/support/block_annotate.h", 
       "src/core/support/cmdline.c", 
       "src/core/support/cpu_iphone.c", 
diff --git a/tools/run_tests/tests.json b/tools/run_tests/tests.json
index 2be7d8a48a852e3ea73bb3ef645c62d37fadf965..de6496028a46d37e1b427cf46235f08fc1644e0a 100644
--- a/tools/run_tests/tests.json
+++ b/tools/run_tests/tests.json
@@ -453,6 +453,27 @@
       "windows"
     ]
   }, 
+  {
+    "args": [], 
+    "ci_platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "flaky": false, 
+    "gtest": false, 
+    "language": "c", 
+    "name": "gpr_backoff_test", 
+    "platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ]
+  }, 
   {
     "args": [], 
     "ci_platforms": [
@@ -1272,7 +1293,7 @@
     ], 
     "cpu_cost": 0.1, 
     "exclude_configs": [], 
-    "flaky": false, 
+    "flaky": true, 
     "gtest": false, 
     "language": "c", 
     "name": "lb_policies_test", 
@@ -2295,7 +2316,7 @@
       "mac", 
       "posix"
     ], 
-    "cpu_cost": 10, 
+    "cpu_cost": 0.5, 
     "exclude_configs": [], 
     "flaky": false, 
     "gtest": false, 
diff --git a/vsprojects/buildtests_c.sln b/vsprojects/buildtests_c.sln
index 2092162f61bd78d859ff24f234cce99628aaf280..752fac7483800f43b4eaa85bb1f7e94f2e1cfac0 100644
--- a/vsprojects/buildtests_c.sln
+++ b/vsprojects/buildtests_c.sln
@@ -334,6 +334,15 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "gpr_avl_test", "vcxproj\tes
 		{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792} = {B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}
 	EndProjectSection
 EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "gpr_backoff_test", "vcxproj\test\gpr_backoff_test\gpr_backoff_test.vcxproj", "{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}"
+	ProjectSection(myProperties) = preProject
+        	lib = "False"
+	EndProjectSection
+	ProjectSection(ProjectDependencies) = postProject
+		{EAB0A629-17A9-44DB-B5FF-E91A721FE037} = {EAB0A629-17A9-44DB-B5FF-E91A721FE037}
+		{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792} = {B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}
+	EndProjectSection
+EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "gpr_cmdline_test", "vcxproj\test\gpr_cmdline_test\gpr_cmdline_test.vcxproj", "{10668A5D-65CD-F530-22D0-747B395B4C26}"
 	ProjectSection(myProperties) = preProject
         	lib = "False"
@@ -1868,6 +1877,22 @@ Global
 		{144D8CFF-2737-A18A-DCFD-01603533D63F}.Release-DLL|Win32.Build.0 = Release|Win32
 		{144D8CFF-2737-A18A-DCFD-01603533D63F}.Release-DLL|x64.ActiveCfg = Release|x64
 		{144D8CFF-2737-A18A-DCFD-01603533D63F}.Release-DLL|x64.Build.0 = Release|x64
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Debug|Win32.ActiveCfg = Debug|Win32
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Debug|x64.ActiveCfg = Debug|x64
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Release|Win32.ActiveCfg = Release|Win32
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Release|x64.ActiveCfg = Release|x64
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Debug|Win32.Build.0 = Debug|Win32
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Debug|x64.Build.0 = Debug|x64
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Release|Win32.Build.0 = Release|Win32
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Release|x64.Build.0 = Release|x64
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Debug-DLL|Win32.ActiveCfg = Debug|Win32
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Debug-DLL|Win32.Build.0 = Debug|Win32
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Debug-DLL|x64.ActiveCfg = Debug|x64
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Debug-DLL|x64.Build.0 = Debug|x64
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Release-DLL|Win32.ActiveCfg = Release|Win32
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Release-DLL|Win32.Build.0 = Release|Win32
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Release-DLL|x64.ActiveCfg = Release|x64
+		{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}.Release-DLL|x64.Build.0 = Release|x64
 		{10668A5D-65CD-F530-22D0-747B395B4C26}.Debug|Win32.ActiveCfg = Debug|Win32
 		{10668A5D-65CD-F530-22D0-747B395B4C26}.Debug|x64.ActiveCfg = Debug|x64
 		{10668A5D-65CD-F530-22D0-747B395B4C26}.Release|Win32.ActiveCfg = Release|Win32
diff --git a/vsprojects/vcxproj/gpr/gpr.vcxproj b/vsprojects/vcxproj/gpr/gpr.vcxproj
index dae8e623d82238e8127bff924ac338ec5d3f64d9..9281fa399522a81db70ee8563d429308a70acef2 100644
--- a/vsprojects/vcxproj/gpr/gpr.vcxproj
+++ b/vsprojects/vcxproj/gpr/gpr.vcxproj
@@ -192,6 +192,7 @@
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="$(SolutionDir)\..\src\core\profiling\timers.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\support\backoff.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\support\block_annotate.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\support\env.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\support\load_file.h" />
@@ -212,6 +213,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\support\avl.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\support\backoff.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\support\cmdline.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\support\cpu_iphone.c">
diff --git a/vsprojects/vcxproj/gpr/gpr.vcxproj.filters b/vsprojects/vcxproj/gpr/gpr.vcxproj.filters
index 055b29f64809ab6335f02e5961a55902b2780b12..b85060f385042026c113550b39ead6dc21008b69 100644
--- a/vsprojects/vcxproj/gpr/gpr.vcxproj.filters
+++ b/vsprojects/vcxproj/gpr/gpr.vcxproj.filters
@@ -13,6 +13,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\support\avl.c">
       <Filter>src\core\support</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\support\backoff.c">
+      <Filter>src\core\support</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\support\cmdline.c">
       <Filter>src\core\support</Filter>
     </ClCompile>
@@ -263,6 +266,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\profiling\timers.h">
       <Filter>src\core\profiling</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\support\backoff.h">
+      <Filter>src\core\support</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\support\block_annotate.h">
       <Filter>src\core\support</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/test/gpr_backoff_test/gpr_backoff_test.vcxproj b/vsprojects/vcxproj/test/gpr_backoff_test/gpr_backoff_test.vcxproj
new file mode 100644
index 0000000000000000000000000000000000000000..6aa292ef4f562ba8a5b7a50bf77f12f6a14fb623
--- /dev/null
+++ b/vsprojects/vcxproj/test/gpr_backoff_test/gpr_backoff_test.vcxproj
@@ -0,0 +1,193 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\1.0.204.1.props')" />
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{889F570D-E046-BD52-9E4C-B4CD13DFE2DB}</ProjectGuid>
+    <IgnoreWarnIntDirInTempDetected>true</IgnoreWarnIntDirInTempDetected>
+    <IntDir>$(SolutionDir)IntDir\$(MSBuildProjectName)\</IntDir>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '10.0'" Label="Configuration">
+    <PlatformToolset>v100</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '11.0'" Label="Configuration">
+    <PlatformToolset>v110</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '12.0'" Label="Configuration">
+    <PlatformToolset>v120</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '14.0'" Label="Configuration">
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+    <Import Project="$(SolutionDir)\..\vsprojects\global.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\openssl.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\winsock.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\zlib.props" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'">
+    <TargetName>gpr_backoff_test</TargetName>
+    <Linkage-grpc_dependencies_zlib>static</Linkage-grpc_dependencies_zlib>
+    <Configuration-grpc_dependencies_zlib>Debug</Configuration-grpc_dependencies_zlib>
+    <Linkage-grpc_dependencies_openssl>static</Linkage-grpc_dependencies_openssl>
+    <Configuration-grpc_dependencies_openssl>Debug</Configuration-grpc_dependencies_openssl>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'">
+    <TargetName>gpr_backoff_test</TargetName>
+    <Linkage-grpc_dependencies_zlib>static</Linkage-grpc_dependencies_zlib>
+    <Configuration-grpc_dependencies_zlib>Release</Configuration-grpc_dependencies_zlib>
+    <Linkage-grpc_dependencies_openssl>static</Linkage-grpc_dependencies_openssl>
+    <Configuration-grpc_dependencies_openssl>Release</Configuration-grpc_dependencies_openssl>
+  </PropertyGroup>
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+    </Link>
+  </ItemDefinitionGroup>
+
+  <ItemGroup>
+    <ClCompile Include="$(SolutionDir)\..\test\core\support\backoff_test.c">
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\gpr_test_util\gpr_test_util.vcxproj">
+      <Project>{EAB0A629-17A9-44DB-B5FF-E91A721FE037}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\gpr\gpr.vcxproj">
+      <Project>{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}</Project>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies\grpc.dependencies.zlib.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies.zlib.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies\grpc.dependencies.zlib.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies\grpc.dependencies.openssl.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies\grpc.dependencies.openssl.targets')" />
+  </ImportGroup>
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets')" />
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+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets')" />
+  </Target>
+</Project>
+
diff --git a/vsprojects/vcxproj/test/gpr_backoff_test/gpr_backoff_test.vcxproj.filters b/vsprojects/vcxproj/test/gpr_backoff_test/gpr_backoff_test.vcxproj.filters
new file mode 100644
index 0000000000000000000000000000000000000000..eb3c1bbd8c287e477ee4481730ad8232e5bd5858
--- /dev/null
+++ b/vsprojects/vcxproj/test/gpr_backoff_test/gpr_backoff_test.vcxproj.filters
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <ClCompile Include="$(SolutionDir)\..\test\core\support\backoff_test.c">
+      <Filter>test\core\support</Filter>
+    </ClCompile>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Filter Include="test">
+      <UniqueIdentifier>{4b7f1d25-d344-0bcb-63d8-2ba959874ea8}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="test\core">
+      <UniqueIdentifier>{2bd2fba5-8799-2c78-469f-ec3ba6b01da8}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="test\core\support">
+      <UniqueIdentifier>{2ef0cfa7-fe3d-2b82-7d0e-f9e293e8f98c}</UniqueIdentifier>
+    </Filter>
+  </ItemGroup>
+</Project>
+