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

webrtc/pc/channel.h

Index: webrtc/pc/channel.h
diff --git a/webrtc/pc/channel.h b/webrtc/pc/channel.h
index 48259e5fd9d7732b94c4deaa817265edf5b85b59..8871bd83afd0bceb0871a9abc653470f197d9870 100644
--- a/webrtc/pc/channel.h
+++ b/webrtc/pc/channel.h
@@ -351,10 +351,9 @@ class BaseChannel
       const std::vector<ConnectionInfo>& infos) = 0;
 
   // Helper function for invoking bool-returning methods on the worker thread.

[hbos, 2017/05/09 12:48:14]

nit: Update comment.

[holmer, 2017/05/30 14:44:28]

Done.

-  template <class FunctorT>
-  bool InvokeOnWorker(const rtc::Location& posted_from,
-                      const FunctorT& functor) {
-    return worker_thread_->Invoke<bool>(posted_from, functor);
+  template <class T, class FunctorT>
+  T InvokeOnWorker(const rtc::Location& posted_from, const FunctorT& functor) {
+    return worker_thread_->Invoke<T>(posted_from, functor);
   }
 
  private:
@@ -554,6 +553,7 @@ class VideoChannel : public BaseChannel {
 
   bool SetSink(uint32_t ssrc,
                rtc::VideoSinkInterface<webrtc::VideoFrame>* sink);
+  void FillBitrateInfo(BandwidthEstimationInfo* bwe_info);

[hbos, 2017/05/09 12:48:14]

Why is this only in VideoChannel and not also in VoiceChannel (virtual in
BaseChannel)?

[holmer, 2017/05/30 14:44:28]

We should probably add it to VoiceChannel later as well. Currently voice bitrate
isn't filled in. That'll have to be in a separate CL though.

[hbos, 2017/05/31 14:31:58]

Acknowledged.

   // Get statistics about the current media session.
   bool GetStats(VideoMediaInfo* stats);