Update MediaStreamTrack::Stop to latest draft.

content/renderer/media/media_stream_video_source.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/media_stream_video_source.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 
@@ skipping 319 matching lines @@
     }
     case ENDED:
     case STARTED: {
       // Currently, reconfiguring the source is not supported.
       FinalizeAddTrack();
     }
   }
 }
 
 void MediaStreamVideoSource::RemoveTrack(MediaStreamVideoTrack* video_track) {
+  DCHECK(CalledOnValidThread());
   std::vector<MediaStreamVideoTrack*>::iterator it =
       std::find(tracks_.begin(), tracks_.end(), video_track);
   DCHECK(it != tracks_.end());
   tracks_.erase(it);
+  if (tracks_.empty())
+    StopSource();
 }
 
 void MediaStreamVideoSource::InitAdapter() {
   if (adapter_)
     return;
   // Create the webrtc::MediaStreamVideoSourceInterface adapter.
   // It needs the constraints so that constraints used by a PeerConnection
   // will be available such as constraints for CPU adaptation and a tab
   // capture.
   bool is_screencast =
       device_info().device.type == MEDIA_TAB_VIDEO_CAPTURE ||
       device_info().device.type == MEDIA_DESKTOP_VIDEO_CAPTURE;
   capture_adapter_ = factory_->CreateVideoCapturer(is_screencast);
   capture_adapter_->SetRequestedFormat(current_format_);
   adapter_ = factory_->CreateVideoSource(capture_adapter_,
                                          current_constraints_);
 }
 
 webrtc::VideoSourceInterface* MediaStreamVideoSource::GetAdapter() {
   if (!adapter_) {
     InitAdapter();
   }
   return adapter_;
 }
 
 void MediaStreamVideoSource::DoStopSource() {
+  DCHECK(CalledOnValidThread());
   DVLOG(3) << "DoStopSource()";
   StopSourceImpl();
   state_ = ENDED;
   SetReadyState(blink::WebMediaStreamSource::ReadyStateEnded);
 }
 
 void MediaStreamVideoSource::DeliverVideoFrame(
     const scoped_refptr<media::VideoFrame>& frame) {
   scoped_refptr<media::VideoFrame> video_frame(frame);
 
@@ skipping 131 matching lines @@
 MediaStreamVideoSource::RequestedConstraints::RequestedConstraints(
     const blink::WebMediaConstraints& constraints,
     const ConstraintsCallback& callback)
     : constraints(constraints), callback(callback) {
 }
 
 MediaStreamVideoSource::RequestedConstraints::~RequestedConstraints() {
 }
 
 }  // namespace content