Merge github.com:grpc/grpc into slice_with_exec_ctx

.gitmodules

Makefile

build.yaml

src/benchmark/gen_build_yaml.py

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/cronet/transport/cronet_transport.c

src/core/lib/iomgr/tcp_posix.c

src/core/lib/surface/completion_queue.c

src/node/performance/worker_service_impl.js

...e-c/tests/CoreCronetEnd2EndTests/CoreCronetEnd2EndTests.m

test/cpp/microbenchmarks/bm_fullstack.cc

test/cpp/microbenchmarks/noop-benchmark.cc

test/cpp/qps/driver.cc

third_party/benchmark

tools/buildgen/generate_build_additions.sh

tools/gce/linux_performance_worker_init.sh

tools/run_tests/build_python.sh

...s/run_tests/performance/process_local_perf_flamegraphs.sh