Propagate MediaStreamSource state to video tracks the same way as audio.

webrtc/api/videotrack.cc

 /*
  *  Copyright 2011 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.
  */
 
 #include "webrtc/api/videotrack.h"
 
 #include <string>
 
 namespace webrtc {
 
 const char MediaStreamTrackInterface::kVideoKind[] = "video";
 
 VideoTrack::VideoTrack(const std::string& label,
                        VideoTrackSourceInterface* video_source)
     : MediaStreamTrack<VideoTrackInterface>(label),
       video_source_(video_source) {
+  video_source_->RegisterObserver(this);
 }
 
 VideoTrack::~VideoTrack() {
+  video_source_->UnregisterObserver(this);
 }
 
 std::string VideoTrack::kind() const {
   return kVideoKind;
 }
 
 void VideoTrack::AddOrUpdateSink(
     rtc::VideoSinkInterface<cricket::VideoFrame>* sink,
     const rtc::VideoSinkWants& wants) {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
@@ skipping 13 matching lines @@
 bool VideoTrack::set_enabled(bool enable) {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   for (auto& sink_pair : sink_pairs()) {
     rtc::VideoSinkWants modified_wants = sink_pair.wants;
     modified_wants.black_frames = !enable;
     video_source_->AddOrUpdateSink(sink_pair.sink, modified_wants);
   }
   return MediaStreamTrack<VideoTrackInterface>::set_enabled(enable);
 }
 
+void VideoTrack::OnChanged() {
+  RTC_DCHECK(thread_checker_.CalledOnValidThread());
+  if (video_source_->state() == MediaSourceInterface::kEnded) {
+    set_state(kEnded);
+  } else {
+    set_state(kLive);
+  }
+}
+
 rtc::scoped_refptr<VideoTrack> VideoTrack::Create(
     const std::string& id,
     VideoTrackSourceInterface* source) {
   rtc::RefCountedObject<VideoTrack>* track =
       new rtc::RefCountedObject<VideoTrack>(id, source);
   return track;
 }
 
 }  // namespace webrtc