Wire up BWE stats through WebrtcSession so that they are filled in both for audio and video calls.

webrtc/pc/channel.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 1969 matching lines @@
   // and we have had some form of connectivity.
   bool send = IsReadyToSendMedia_w();
   if (!media_channel()->SetSend(send)) {
     LOG(LS_ERROR) << "Failed to SetSend on video channel";
     // TODO(gangji): Report error back to server.
   }
 
   LOG(LS_INFO) << "Changing video state, send=" << send;
 }
 
+void VideoChannel::FillBitrateInfo(BandwidthEstimationInfo* bwe_info) {
+  RTC_DCHECK(InvokeOnWorker(

[Taylor Brandstetter, 2017/05/07 21:30:44]

Why is this in an RTC_DCHECK?

[stefan-webrtc, 2017/05/08 07:12:56]

Copy paste from below, but my method didn't have to return bool... Changed it
now to call worker_thread_->Invoke<void>() instead.

+      RTC_FROM_HERE,
+      Bind(&VideoMediaChannel::FillBitrateInfo, media_channel(), bwe_info)));
+}
+
 bool VideoChannel::GetStats(VideoMediaInfo* stats) {
   return InvokeOnWorker(RTC_FROM_HERE, Bind(&VideoMediaChannel::GetStats,
                                             media_channel(), stats));
 }
 
 void VideoChannel::StartMediaMonitor(int cms) {
   media_monitor_.reset(new VideoMediaMonitor(media_channel(), worker_thread(),
       rtc::Thread::Current()));
   media_monitor_->SignalUpdate.connect(
       this, &VideoChannel::OnMediaMonitorUpdate);
@@ skipping 400 matching lines @@
 
 void RtpDataChannel::OnDataChannelReadyToSend(bool writable) {
   // This is usded for congestion control to indicate that the stream is ready
   // to send by the MediaChannel, as opposed to OnReadyToSend, which indicates
   // that the transport channel is ready.
   signaling_thread()->Post(RTC_FROM_HERE, this, MSG_READYTOSENDDATA,
                            new DataChannelReadyToSendMessageData(writable));
 }
 
 }  // namespace cricket