add trace context proto
diff --git a/binding.gyp b/binding.gyp
index a29cfda..666547c 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -742,6 +742,7 @@
         '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',