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

content/renderer/media/webrtc_audio_renderer.cc

Index: content/renderer/media/webrtc_audio_renderer.cc
===================================================================
--- content/renderer/media/webrtc_audio_renderer.cc	(revision 275847)
+++ content/renderer/media/webrtc_audio_renderer.cc	(working copy)
@@ -450,7 +450,9 @@
 }
 
 base::TimeDelta WebRtcAudioRenderer::GetCurrentRenderTime() const {
-  return base::TimeDelta();
+  DCHECK(thread_checker_.CalledOnValidThread());
+  base::AutoLock auto_lock(lock_);
+  return current_time_;
 }
 
 bool WebRtcAudioRenderer::IsLocalRenderer() const {
@@ -495,7 +497,8 @@
   // We need to keep render data for the |source_| regardless of |state_|,
   // otherwise the data will be buffered up inside |source_|.
   source_->RenderData(audio_bus, sink_params_.sample_rate(),
-                      output_delay_milliseconds);
+                      output_delay_milliseconds,
+                      &current_time_);
 
   // Avoid filling up the audio bus if we are not playing; instead
   // return here and ensure that the returned value in Render() is 0.