Change audio render thread checking to use new AudioRendererSink::BelongsToRendererThread()

content/renderer/media/webrtc_audio_renderer.h

Index: content/renderer/media/webrtc_audio_renderer.h
diff --git a/content/renderer/media/webrtc_audio_renderer.h b/content/renderer/media/webrtc_audio_renderer.h
index f13ac8d5befdc790b894f6e8dd9f9dde13d74244..267d0557d7c5dfd51bc871f65b0d629cc9c97b77 100644
--- a/content/renderer/media/webrtc_audio_renderer.h
+++ b/content/renderer/media/webrtc_audio_renderer.h
@@ -109,6 +109,9 @@ class CONTENT_EXPORT WebRtcAudioRenderer
   int sample_rate() const { return sink_params_.sample_rate(); }
   int frames_per_buffer() const { return sink_params_.frames_per_buffer(); }
 
+  // Returns true if called on rendering thread, otherwise false.
+  bool BelongsToRenderingThread();
+
  private:
   // MediaStreamAudioRenderer implementation.  This is private since we want
   // callers to use proxy objects.
@@ -155,7 +158,6 @@ class CONTENT_EXPORT WebRtcAudioRenderer
 
   // Used to DCHECK that we are called on the correct thread.
   base::ThreadChecker thread_checker_;
-  base::ThreadChecker audio_renderer_thread_checker_;
 
   // Flag to keep track the state of the renderer.
   State state_;