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

BUILD

CMakeLists.txt

Makefile

binding.gyp

build.yaml

config.m4

gRPC-Core.podspec

grpc.gemspec

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

package.xml

src/core/ext/filters/client_channel/client_channel.c

src/core/ext/filters/client_channel/lb_policy.c

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

...t_channel/lb_policy/grpclb/client_load_reporting_filter.c

...t_channel/lb_policy/grpclb/client_load_reporting_filter.h

...core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c

...ers/client_channel/lb_policy/grpclb/grpclb_client_stats.c

...ers/client_channel/lb_policy/grpclb/grpclb_client_stats.h

...lters/client_channel/lb_policy/grpclb/load_balancer_api.c

...lters/client_channel/lb_policy/grpclb/load_balancer_api.h