add trace context proto
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 41ba1b1..900ea41 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -407,6 +407,7 @@
'src/core/ext/census/census_interface.h',
'src/core/ext/census/census_rpc_stats.h',
'src/core/ext/census/gen/census.pb.h',
+ 'src/core/ext/census/gen/trace_context.pb.h',
'src/core/ext/census/grpc_filter.h',
'src/core/ext/census/mlog.h',
'src/core/ext/census/resource.h',
@@ -591,6 +592,7 @@
'src/core/ext/census/base_resources.c',
'src/core/ext/census/context.c',
'src/core/ext/census/gen/census.pb.c',
+ 'src/core/ext/census/gen/trace_context.pb.c',
'src/core/ext/census/grpc_context.c',
'src/core/ext/census/grpc_filter.c',
'src/core/ext/census/grpc_plugin.c',
@@ -768,6 +770,7 @@
'src/core/ext/census/census_interface.h',
'src/core/ext/census/census_rpc_stats.h',
'src/core/ext/census/gen/census.pb.h',
+ 'src/core/ext/census/gen/trace_context.pb.h',
'src/core/ext/census/grpc_filter.h',
'src/core/ext/census/mlog.h',
'src/core/ext/census/resource.h',