Require negotiation to send transport cc feedback over RTCP.

talk/media/base/codec.cc

 /*
  * libjingle
  * Copyright 2004 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 316 matching lines @@
 bool HasNack(const VideoCodec& codec) {
   return codec.HasFeedbackParam(
       FeedbackParam(kRtcpFbParamNack, kParamValueEmpty));
 }
 
 bool HasRemb(const VideoCodec& codec) {
   return codec.HasFeedbackParam(
       FeedbackParam(kRtcpFbParamRemb, kParamValueEmpty));
 }
 
+bool HasTransportCcFeedback(const VideoCodec& codec) {

[pthatcher, 2015/11/19 00:19:20]

I think just HasTransportCc would be sufficient and match HasRemb and HasNack.

[stefan-webrtc, 2015/11/20 16:58:48]

Done.

+  return codec.HasFeedbackParam(
+      FeedbackParam(kRtcpFbParamTransportCc, kParamValueEmpty));
+}
+
 bool CodecNamesEq(const std::string& name1, const std::string& name2) {
   return _stricmp(name1.c_str(), name2.c_str()) == 0;
 }
 
 }  // namespace cricket