Potential fix for rtx/red issue where red is removed only from the remote description.

webrtc/modules/rtp_rtcp/source/rtp_payload_registry.cc

 /*
  *  Copyright (c) 2013 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 89 matching lines @@
         payload_name, payload_name_length, frequency, channels, rate);
   }
 
   RtpUtility::Payload* payload = rtp_payload_strategy_->CreatePayloadType(
       payload_name, payload_type, frequency, channels, rate);
 
   payload_type_map_[payload_type] = payload;
   *created_new_payload = true;
 
   if (RtpUtility::StringCompare(payload_name, "red", 3)) {
+    LOG(LS_ERROR) << "Red enabled: " << static_cast<int>(payload_type);
     red_payload_type_ = payload_type;
   } else if (RtpUtility::StringCompare(payload_name, "ulpfec", 6)) {
     ulpfec_payload_type_ = payload_type;
   }
 
   // Successful set of payload type, clear the value of last received payload
   // type since it might mean something else.
   last_received_payload_type_ = -1;
   last_received_media_payload_type_ = -1;
   return 0;
 }
 
 int32_t RTPPayloadRegistry::DeRegisterReceivePayload(
     const int8_t payload_type) {
   rtc::CritScope cs(&crit_sect_);
   RtpUtility::PayloadTypeMap::iterator it =
       payload_type_map_.find(payload_type);
+  if (red_payload_type_ == payload_type) {
+    LOG(LS_ERROR) << "Red disabled";
+    red_payload_type_ = -1;
+  }
   assert(it != payload_type_map_.end());
   delete it->second;
   payload_type_map_.erase(it);
   return 0;
 }
 
 // There can't be several codecs with the same rate, frequency and channels
 // for audio codecs, but there can for video.
 // Always called from within a critical section.
 void RTPPayloadRegistry::DeregisterAudioCodecOrRedTypeRegardlessOfPayloadType(
@@ skipping 126 matching lines @@
   if (apt_mapping == rtx_payload_type_map_.end())
     return false;
   associated_payload_type = apt_mapping->second;
   if (red_payload_type_ != -1) {
     // Assume red will be used if it's configured.
     // This is a workaround for a Chrome sdp bug where rtx is associated
     // with the media codec even though media is sent over red.
     // TODO(holmer): Remove once the Chrome versions exposing this bug are
     // old enough, which should be once Chrome Stable reaches M53 as this
     // work-around went into M50.
+    LOG(LS_ERROR) << "Assuming red payload: "
+                  << static_cast<int>(red_payload_type_);
     associated_payload_type = red_payload_type_;
   }
   restored_packet[1] = static_cast<uint8_t>(associated_payload_type);
   if (header.markerBit) {
     restored_packet[1] |= kRtpMarkerBitMask;  // Marker bit is set.
   }
   return true;
 }
 
 void RTPPayloadRegistry::SetRtxSsrc(uint32_t ssrc) {
@@ skipping 183 matching lines @@
 RTPPayloadStrategy* RTPPayloadStrategy::CreateStrategy(
     const bool handling_audio) {
   if (handling_audio) {
     return new RTPPayloadAudioStrategy();
   } else {
     return new RTPPayloadVideoStrategy();
   }
 }
 
 }  // namespace webrtc