Added mute logic to VideoTrackRenderers.

talk/app/webrtc/peerconnectionfactory_unittest.cc

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 342 matching lines @@
       factory_->CreateVideoSource(capturer, NULL));
   ASSERT_TRUE(source.get() != NULL);
   rtc::scoped_refptr<VideoTrackInterface> track(
       factory_->CreateVideoTrack("testlabel", source));
   ASSERT_TRUE(track.get() != NULL);
   FakeVideoTrackRenderer local_renderer(track);
 
   EXPECT_EQ(0, local_renderer.num_rendered_frames());
   EXPECT_TRUE(capturer->CaptureFrame());
   EXPECT_EQ(1, local_renderer.num_rendered_frames());
+  EXPECT_FALSE(local_renderer.black_frame());
 
   track->set_enabled(false);
   EXPECT_TRUE(capturer->CaptureFrame());
-  EXPECT_EQ(1, local_renderer.num_rendered_frames());
+  EXPECT_EQ(2, local_renderer.num_rendered_frames());
+  EXPECT_TRUE(local_renderer.black_frame());
 
   track->set_enabled(true);
   EXPECT_TRUE(capturer->CaptureFrame());
-  EXPECT_EQ(2, local_renderer.num_rendered_frames());
+  EXPECT_EQ(3, local_renderer.num_rendered_frames());
+  EXPECT_FALSE(local_renderer.black_frame());
 }
-