Merge remote-tracking branch 'upstream/master' into client_channel_init_cleanup

.gitmodules

Makefile

build.yaml

include/grpc++/impl/codegen/completion_queue.h

include/grpc++/impl/codegen/server_interface.h

src/benchmark/gen_build_yaml.py

src/core/ext/transport/chttp2/client/chttp2_connector.c

src/core/ext/transport/chttp2/server/chttp2_server.c

src/core/ext/transport/chttp2/server/chttp2_server.h

...core/ext/transport/chttp2/server/insecure/server_chttp2.c

...ext/transport/chttp2/server/secure/server_secure_chttp2.c

src/core/ext/transport/chttp2/transport/chttp2_transport.c

src/core/ext/transport/chttp2/transport/internal.h

src/core/ext/transport/chttp2/transport/stream_lists.c

src/core/ext/transport/chttp2/transport/writing.c

src/core/ext/transport/cronet/transport/cronet_transport.c

src/core/lib/iomgr/tcp_posix.c

src/core/lib/surface/call.c

src/core/lib/surface/completion_queue.c

src/cpp/common/completion_queue_cc.cc