Don't cache video codec list in VideoEngine2.

webrtc/pc/channelmanager.cc

 /*
  *  Copyright 2004 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 123 matching lines @@
 
 void ChannelManager::GetSupportedAudioRtpHeaderExtensions(
     RtpHeaderExtensions* ext) const {
   *ext = media_engine_->GetAudioCapabilities().header_extensions;
 }
 
 void ChannelManager::GetSupportedVideoCodecs(
     std::vector<VideoCodec>* codecs) const {
   codecs->clear();
 
-  std::vector<VideoCodec>::const_iterator it;
-  for (it = media_engine_->video_codecs().begin();
-      it != media_engine_->video_codecs().end(); ++it) {
-    if (!enable_rtx_ && _stricmp(kRtxCodecName, it->name.c_str()) == 0) {
+  std::vector<VideoCodec> video_codecs = media_engine_->video_codecs();
+  for (const auto& video_codec : video_codecs) {
+    if (!enable_rtx_ &&
+        _stricmp(kRtxCodecName, video_codec.name.c_str()) == 0) {
       continue;
     }
-    codecs->push_back(*it);
+    codecs->push_back(video_codec);
   }
 }
 
 void ChannelManager::GetSupportedVideoRtpHeaderExtensions(
     RtpHeaderExtensions* ext) const {
   *ext = media_engine_->GetVideoCapabilities().header_extensions;
 }
 
 void ChannelManager::GetSupportedDataCodecs(
     std::vector<DataCodec>* codecs) const {
@@ skipping 250 matching lines @@
                           media_engine_.get(), file, max_size_bytes));
 }
 
 void ChannelManager::StopAecDump() {
   worker_thread_->Invoke<void>(
       RTC_FROM_HERE,
       Bind(&MediaEngineInterface::StopAecDump, media_engine_.get()));
 }
 
 }  // namespace cricket