Revert "Revert "Channel Tracing Implementation; Part 1""

This reverts commit f2bea3725f8218777268decfd37c7b543f839d9f.
diff --git a/grpc.gemspec b/grpc.gemspec
index 3a57829..3b07dd6 100644
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -267,7 +267,6 @@
   s.files += %w( src/core/ext/filters/client_channel/resolver_factory.h )
   s.files += %w( src/core/ext/filters/client_channel/resolver_registry.h )
   s.files += %w( src/core/ext/filters/client_channel/retry_throttle.h )
-  s.files += %w( src/core/ext/filters/client_channel/status_util.h )
   s.files += %w( src/core/ext/filters/client_channel/subchannel.h )
   s.files += %w( src/core/ext/filters/client_channel/subchannel_index.h )
   s.files += %w( src/core/ext/filters/client_channel/uri_parser.h )
@@ -284,11 +283,14 @@
   s.files += %w( src/core/lib/channel/channel_args.h )
   s.files += %w( src/core/lib/channel/channel_stack.h )
   s.files += %w( src/core/lib/channel/channel_stack_builder.h )
+  s.files += %w( src/core/lib/channel/channel_trace.h )
+  s.files += %w( src/core/lib/channel/channel_trace_registry.h )
   s.files += %w( src/core/lib/channel/connected_channel.h )
   s.files += %w( src/core/lib/channel/context.h )
   s.files += %w( src/core/lib/channel/handshaker.h )
   s.files += %w( src/core/lib/channel/handshaker_factory.h )
   s.files += %w( src/core/lib/channel/handshaker_registry.h )
+  s.files += %w( src/core/lib/channel/status_util.h )
   s.files += %w( src/core/lib/compression/algorithm_metadata.h )
   s.files += %w( src/core/lib/compression/compression_internal.h )
   s.files += %w( src/core/lib/compression/message_compress.h )
@@ -430,10 +432,13 @@
   s.files += %w( src/core/lib/channel/channel_args.cc )
   s.files += %w( src/core/lib/channel/channel_stack.cc )
   s.files += %w( src/core/lib/channel/channel_stack_builder.cc )
+  s.files += %w( src/core/lib/channel/channel_trace.cc )
+  s.files += %w( src/core/lib/channel/channel_trace_registry.cc )
   s.files += %w( src/core/lib/channel/connected_channel.cc )
   s.files += %w( src/core/lib/channel/handshaker.cc )
   s.files += %w( src/core/lib/channel/handshaker_factory.cc )
   s.files += %w( src/core/lib/channel/handshaker_registry.cc )
+  s.files += %w( src/core/lib/channel/status_util.cc )
   s.files += %w( src/core/lib/compression/compression.cc )
   s.files += %w( src/core/lib/compression/compression_internal.cc )
   s.files += %w( src/core/lib/compression/message_compress.cc )
@@ -682,7 +687,6 @@
   s.files += %w( src/core/ext/filters/client_channel/resolver.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver_registry.cc )
   s.files += %w( src/core/ext/filters/client_channel/retry_throttle.cc )
-  s.files += %w( src/core/ext/filters/client_channel/status_util.cc )
   s.files += %w( src/core/ext/filters/client_channel/subchannel.cc )
   s.files += %w( src/core/ext/filters/client_channel/subchannel_index.cc )
   s.files += %w( src/core/ext/filters/client_channel/uri_parser.cc )