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

webrtc/pc/videotrack.cc

Index: webrtc/pc/videotrack.cc
diff --git a/webrtc/pc/videotrack.cc b/webrtc/pc/videotrack.cc
index f106460164731f4b32facb3201403a4c3e6bf66c..494d728b1eaad2ba204308cbb84f708af2706304 100644
--- a/webrtc/pc/videotrack.cc
+++ b/webrtc/pc/videotrack.cc
@@ -15,12 +15,11 @@
 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);
 }
 
@@ -36,7 +35,7 @@
 // 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();
@@ -44,7 +43,7 @@
 }
 
 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);
 }
@@ -64,14 +63,13 @@
 
 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);
 }
 
@@ -86,10 +84,9 @@
 
 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;
 }