Revert: Change VideoTrack implementation to invoke VideoTrackSourceInterface::AddOrUpdateSink on wt

webrtc/pc/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/pc/videotrack.h"
 
 #include <string>
 
 namespace webrtc {
 
 VideoTrack::VideoTrack(const std::string& label,
-                       VideoTrackSourceInterface* video_source,
-                       rtc::Thread* worker_thread)
+                       VideoTrackSourceInterface* video_source)
     : MediaStreamTrack<VideoTrackInterface>(label),
-      worker_thread_(worker_thread),
       video_source_(video_source),
       content_hint_(ContentHint::kNone) {
+  worker_thread_checker_.DetachFromThread();
   video_source_->RegisterObserver(this);
 }
 
 VideoTrack::~VideoTrack() {
   video_source_->UnregisterObserver(this);
 }
 
 std::string VideoTrack::kind() const {
   return kVideoKind;
 }
 
 // AddOrUpdateSink and RemoveSink should be called on the worker
 // thread.
 void VideoTrack::AddOrUpdateSink(rtc::VideoSinkInterface<VideoFrame>* sink,
                                  const rtc::VideoSinkWants& wants) {
-  RTC_DCHECK(worker_thread_->IsCurrent());
+  RTC_DCHECK(worker_thread_checker_.CalledOnValidThread());
   VideoSourceBase::AddOrUpdateSink(sink, wants);
   rtc::VideoSinkWants modified_wants = wants;
   modified_wants.black_frames = !enabled();
   video_source_->AddOrUpdateSink(sink, modified_wants);
 }
 
 void VideoTrack::RemoveSink(rtc::VideoSinkInterface<VideoFrame>* sink) {
-  RTC_DCHECK(worker_thread_->IsCurrent());
+  RTC_DCHECK(worker_thread_checker_.CalledOnValidThread());
   VideoSourceBase::RemoveSink(sink);
   video_source_->RemoveSink(sink);
 }
 
 VideoTrackInterface::ContentHint VideoTrack::content_hint() const {
   RTC_DCHECK_RUN_ON(&signaling_thread_checker_);
   return content_hint_;
 }
 
 void VideoTrack::set_content_hint(ContentHint hint) {
   RTC_DCHECK_RUN_ON(&signaling_thread_checker_);
   if (content_hint_ == hint)
     return;
   content_hint_ = hint;
   Notifier<VideoTrackInterface>::FireOnChanged();
 }
 
 bool VideoTrack::set_enabled(bool enable) {
   RTC_DCHECK(signaling_thread_checker_.CalledOnValidThread());
-  worker_thread_->Invoke<void>(RTC_FROM_HERE, [enable, this] {
-    RTC_DCHECK(worker_thread_->IsCurrent());
-    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);
-    }
-  });
+  for (auto& sink_pair : sink_pairs()) {
+    rtc::VideoSinkWants modified_wants = sink_pair.wants;
+    modified_wants.black_frames = !enable;
+    // video_source_ is a proxy object, marshalling the call to the
+    // worker thread.
+    video_source_->AddOrUpdateSink(sink_pair.sink, modified_wants);
+  }
   return MediaStreamTrack<VideoTrackInterface>::set_enabled(enable);
 }
 
 void VideoTrack::OnChanged() {
   RTC_DCHECK(signaling_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::Thread* worker_thread) {
+    VideoTrackSourceInterface* source) {
   rtc::RefCountedObject<VideoTrack>* track =
-      new rtc::RefCountedObject<VideoTrack>(id, source, worker_thread);
+      new rtc::RefCountedObject<VideoTrack>(id, source);
   return track;
 }
 
 }  // namespace webrtc