Explicitly only add transport-cc RTCP feedback param to default FlexFEC codec.

webrtc/media/engine/webrtcvideoengine2.cc

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 553 matching lines @@
     if (!is_payload_used[i - kFirstDynamicPayloadType])
       return rtc::Optional<int>(i);
   }
   // No free payload type.
   return rtc::Optional<int>();
 }
 
 // This is a helper function for GetSupportedCodecs below. It will append new
 // unique codecs from |input_codecs| to |unified_codecs|. It will add default
 // feedback params to the codecs and will also add an associated RTX codec for
-// recognized codecs (VP8, VP9, H264, and Red).
+// recognized codecs (VP8, VP9, H264, and RED).
 static void AppendVideoCodecs(const std::vector<VideoCodec>& input_codecs,
                               std::vector<VideoCodec>* unified_codecs) {
   for (VideoCodec codec : input_codecs) {
     const rtc::Optional<int> payload_type =
         NextFreePayloadType(*unified_codecs);
     if (!payload_type)
       return;
     codec.id = *payload_type;
     // TODO(magjed): Move the responsibility of setting these parameters to the
     // encoder factories instead.
-    if (codec.name != kRedCodecName && codec.name != kUlpfecCodecName)
+    if (codec.name != kRedCodecName && codec.name != kUlpfecCodecName &&
+        codec.name != kFlexfecCodecName)
       AddDefaultFeedbackParams(&codec);
     // Don't add same codec twice.
     if (FindMatchingCodec(*unified_codecs, codec))
       continue;
 
     unified_codecs->push_back(codec);
 
     // Add associated RTX codec for recognized codecs.
     // TODO(deadbeef): Should we add RTX codecs for external codecs whose names
     // we don't recognize?
@@ skipping 1991 matching lines @@
         rtx_mapping[video_codecs[i].codec.id] !=
             ulpfec_config.red_payload_type) {
       video_codecs[i].rtx_payload_type = rtx_mapping[video_codecs[i].codec.id];
     }
   }
 
   return video_codecs;
 }
 
 }  // namespace cricket