Refactor VideoTracks to forward all sinks to its source

webrtc/api/videotrack_unittest.cc

 /*
  *  Copyright 2012 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.
  */
 
@@ skipping 43 matching lines @@
   capturer_.CaptureFrame();
   EXPECT_EQ(1, renderer_1->num_rendered_frames());
 
   // FakeVideoTrackRenderer register itself to |video_track_|
   rtc::scoped_ptr<FakeVideoTrackRenderer> renderer_2(
       new FakeVideoTrackRenderer(video_track_.get()));
   capturer_.CaptureFrame();
   EXPECT_EQ(2, renderer_1->num_rendered_frames());
   EXPECT_EQ(1, renderer_2->num_rendered_frames());
 
-  video_track_->RemoveSink(renderer_1.get());
+  renderer_1.reset(nullptr);
   capturer_.CaptureFrame();
-  EXPECT_EQ(2, renderer_1->num_rendered_frames());
   EXPECT_EQ(2, renderer_2->num_rendered_frames());
 }
 
 // Test adding renderers to a video track and render to them by
 // providing frames to the source. Uses the old VideoTrack interface
 // with AddRenderer and RemoveRenderer.
 TEST_F(VideoTrackTest, RenderVideoOld) {
   // FakeVideoTrackRenderer register itself to |video_track_|
   rtc::scoped_ptr<FakeVideoTrackRendererOld> renderer_1(
       new FakeVideoTrackRendererOld(video_track_.get()));
 
   capturer_.CaptureFrame();
   EXPECT_EQ(1, renderer_1->num_rendered_frames());
 
   // FakeVideoTrackRenderer register itself to |video_track_|
   rtc::scoped_ptr<FakeVideoTrackRenderer> renderer_2(
       new FakeVideoTrackRenderer(video_track_.get()));
 
   capturer_.CaptureFrame();
   EXPECT_EQ(2, renderer_1->num_rendered_frames());
   EXPECT_EQ(1, renderer_2->num_rendered_frames());
 
-  video_track_->RemoveRenderer(renderer_1.get());
+  renderer_1.reset(nullptr);
   capturer_.CaptureFrame();
-  EXPECT_EQ(2, renderer_1->num_rendered_frames());
   EXPECT_EQ(2, renderer_2->num_rendered_frames());
 }
 
 // Test that disabling the track results in blacked out frames.
 TEST_F(VideoTrackTest, DisableTrackBlackout) {
   rtc::scoped_ptr<FakeVideoTrackRenderer> renderer(
       new FakeVideoTrackRenderer(video_track_.get()));
 
   capturer_.CaptureFrame();
   EXPECT_EQ(1, renderer->num_rendered_frames());
   EXPECT_FALSE(renderer->black_frame());
 
   video_track_->set_enabled(false);
   capturer_.CaptureFrame();
   EXPECT_EQ(2, renderer->num_rendered_frames());
   EXPECT_TRUE(renderer->black_frame());
 
   video_track_->set_enabled(true);
   capturer_.CaptureFrame();
   EXPECT_EQ(3, renderer->num_rendered_frames());
   EXPECT_FALSE(renderer->black_frame());
 }