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

Makefile

src/core/iomgr/sockaddr_utils.c

src/core/surface/channel.c

src/cpp/client/channel.cc

src/cpp/client/channel.h

src/cpp/client/create_channel.cc

src/cpp/client/insecure_credentials.cc

src/cpp/client/secure_credentials.cc

...python/grpcio_test/grpc_test/_links/_transmission_test.py

src/python/grpcio_test/grpc_test/test_common.py

templates/Makefile.template

test/core/iomgr/sockaddr_utils_test.c

test/cpp/end2end/generic_end2end_test.cc

third_party/openssl

tools/README.md

tools/run_tests/jobset.py

tools/run_tests/run_sanity.sh