Pass the elapsed time from VoE to WebRtcAudioRenderer as the current time for the audio/video eleme…

content/renderer/media/webrtc_audio_renderer.h

Index: content/renderer/media/webrtc_audio_renderer.h
===================================================================
--- content/renderer/media/webrtc_audio_renderer.h	(revision 275847)
+++ content/renderer/media/webrtc_audio_renderer.h	(working copy)
@@ -100,6 +100,9 @@
   int channels() const { return sink_params_.channels(); }
   int sample_rate() const { return sink_params_.sample_rate(); }
 
+  // This method is called on the AudioOutputDevice worker thread.
+  void SetCurrentRenderTime(const base::TimeDelta& current_time);
+
  private:
   // MediaStreamAudioRenderer implementation.  This is private since we want
   // callers to use proxy objects.
@@ -194,8 +197,8 @@
   // Audio data source from the browser process.
   WebRtcAudioRendererSource* source_;
 
-  // Protects access to |state_|, |source_| and |sink_|.
-  base::Lock lock_;
+  // Protects access to |state_|, |source_|, |sink_| and |current_time_|.
+  mutable base::Lock lock_;
 
   // Ref count for the MediaPlayers which are playing audio.
   int play_ref_count_;
@@ -214,6 +217,8 @@
   // Delay due to the FIFO in milliseconds.
   int fifo_delay_milliseconds_;
 
+  base::TimeDelta current_time_;
+
   // Saved volume and playing state of the root renderer.
   PlayingState playing_state_;