Merge github.com:google/grpc into fast-unref

BUILD

Makefile

build.json

src/core/profiling/timers.c

src/core/profiling/timers.h

src/core/profiling/timers_preciseclock.h

src/core/surface/init.c

src/ruby/.rubocop_todo.yml

src/ruby/CHANGELOG.md

src/ruby/bin/apis/pubsub_demo.rb

src/ruby/bin/interop/interop_client.rb

src/ruby/grpc.gemspec

src/ruby/lib/grpc/generic/client_stub.rb

src/ruby/lib/grpc/version.rb

src/ruby/spec/channel_spec.rb

src/ruby/spec/client_server_spec.rb

src/ruby/spec/generic/rpc_server_spec.rb

src/ruby/spec/server_spec.rb

templates/Makefile.template

test/core/profiling/timers_test.c