Make WebRtcVideoChannel2::WebRtcVideoSendStream implement rtc::VideoRendererInterface.

talk/app/webrtc/rtpsender.cc

 /*
  * libjingle
  * Copyright 2015 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 250 matching lines @@
     LOG(LS_ERROR) << "SetTrack can't be called on a stopped RtpSender.";
     return false;
   }
   if (track && track->kind() != MediaStreamTrackInterface::kVideoKind) {
     LOG(LS_ERROR) << "SetTrack called on video RtpSender with " << track->kind()
                   << " track.";
     return false;
   }
   VideoTrackInterface* video_track = static_cast<VideoTrackInterface*>(track);
 
+  rtc::VideoSinkInterface<cricket::VideoFrame>* sink =
+      provider_->GetSink(ssrc_);
+

[perkj_webrtc, 2016/01/28 13:45:16]

if sinkptr != null.  DCHECK(sinkptr ==provider_->GetSink(ssrc_) and deregister.

[nisse-webrtc, 2016/01/29 07:48:29]

I'm not sure exactly what you mean, but I did something along those lines. I
also added code to SetSsrc, to unregister and reregister.

   // Detach from old track.
   if (track_) {
     track_->UnregisterObserver(this);
+    track_->RemoveSink(sink);
   }
 
   // Attach to new track.
   bool prev_can_send_track = can_send_track();
   track_ = video_track;
   if (track_) {
     cached_track_enabled_ = track_->enabled();
     track_->RegisterObserver(this);
+    video_track->AddSink(sink);
   }
 
   // Update video provider.
   if (can_send_track()) {
     VideoSourceInterface* source = track_->GetSource();
     // TODO(deadbeef): If SetTrack is called with a disabled track, and the
     // previous track was enabled, this could cause a frame from the new track
     // to slip out. Really, what we need is for SetCaptureDevice and
     // SetVideoSend
     // to be combined into one atomic operation, all the way down to
     // WebRtcVideoSendStream.
     provider_->SetCaptureDevice(ssrc_,
                                 source ? source->GetVideoCapturer() : nullptr);

[perkj_webrtc, 2016/01/28 13:45:16]

AddSink here and store the sink in sinkptr. 
When remove dcheck that GetSink returns the same sink.

     SetVideoSend();
   } else if (prev_can_send_track) {
     provider_->SetCaptureDevice(ssrc_, nullptr);
     provider_->SetVideoSend(ssrc_, false, nullptr);
   }
   return true;
 }
 
 void VideoRtpSender::SetSsrc(uint32_t ssrc) {
   if (stopped_ || ssrc == ssrc_) {
@@ skipping 13 matching lines @@
   }
 }
 
 void VideoRtpSender::Stop() {
   // TODO(deadbeef): Need to do more here to fully stop sending packets.
   if (stopped_) {
     return;
   }
   if (track_) {
     track_->UnregisterObserver(this);
+
+    rtc::VideoSinkInterface<cricket::VideoFrame>* sink =

[perkj_webrtc, 2016/01/28 13:45:16]

dito

+        provider_->GetSink(ssrc_);
+    if (sink)
+      track_->RemoveSink(sink);
+    else
+      LOG(LS_ERROR)
+          << "VideoRtpSender::Stop called with a NULL sink. Too late???";
   }
   if (can_send_track()) {
     provider_->SetCaptureDevice(ssrc_, nullptr);
     provider_->SetVideoSend(ssrc_, false, nullptr);
   }
   stopped_ = true;
 }
 
 void VideoRtpSender::SetVideoSend() {
   RTC_DCHECK(!stopped_ && can_send_track());
   const cricket::VideoOptions* options = nullptr;
   VideoSourceInterface* source = track_->GetSource();
   if (track_->enabled() && source) {
     options = source->options();
   }
   provider_->SetVideoSend(ssrc_, track_->enabled(), options);
 }
 
 }  // namespace webrtc