Reviewer comments

src/core/ext/filters/client_channel/client_channel.cc

src/core/ext/filters/client_channel/client_channel_factory.h

.../ext/filters/client_channel/health/health_check_parser.cc

...e/ext/filters/client_channel/health/health_check_parser.h

...ore/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc

src/core/ext/filters/client_channel/lb_policy/xds/xds.cc

src/core/ext/filters/client_channel/lb_policy_registry.cc

src/core/ext/filters/client_channel/lb_policy_registry.h

...ore/ext/filters/client_channel/resolver_result_parsing.cc

...core/ext/filters/client_channel/resolver_result_parsing.h

src/core/ext/filters/client_channel/service_config.cc

src/core/ext/filters/client_channel/service_config.h

src/core/ext/filters/client_channel/subchannel.h

src/core/ext/filters/message_size/message_size_filter.cc

src/core/ext/filters/message_size/message_size_filter.h

test/core/client_channel/service_config_test.cc

test/cpp/microbenchmarks/bm_call_create.cc