Avoid hitting the thread check when WebRtcAudioRenderer is going away.

content/renderer/media/webrtc_audio_renderer.cc

Index: content/renderer/media/webrtc_audio_renderer.cc
diff --git a/content/renderer/media/webrtc_audio_renderer.cc b/content/renderer/media/webrtc_audio_renderer.cc
index edc014a1cbb09d72a2ba1bef7d1fd662ad4dc499..581faaa0a2df99dff77a3e7c2e0b1b55345da983 100644
--- a/content/renderer/media/webrtc_audio_renderer.cc
+++ b/content/renderer/media/webrtc_audio_renderer.cc
@@ -422,6 +422,13 @@ void WebRtcAudioRenderer::EnterPauseState() {
 void WebRtcAudioRenderer::Stop() {
   DVLOG(1) << "WebRtcAudioRenderer::Stop()";
   DCHECK(thread_checker_.CalledOnValidThread());
+  // Make sure to stop the sink while _not_ holding the lock since the Render()
+  // callback may currently be executing and try to grab the lock while we're
+  // stopping the thread on which it runs.
+  // Stop the sink before calling RemoveAudioRenderer() on the source to make
+  // sure that no more callback will get into the source.

[tommi (sloooow) - chröme, 2014/03/04 20:48:39]

nit:
// Stop the sink before calling RemoveAudioRenderer() to make
// sure that no more callbacks will be made while the renderer
// is being removed.

[no longer working on chromium, 2014/03/05 13:01:04]

Done.

+  sink_->Stop();
+
   {
     base::AutoLock auto_lock(lock_);
     if (state_ == UNINITIALIZED)
@@ -436,11 +443,6 @@ void WebRtcAudioRenderer::Stop() {
     source_ = NULL;
     state_ = UNINITIALIZED;
   }
-
-  // Make sure to stop the sink while _not_ holding the lock since the Render()
-  // callback may currently be executing and try to grab the lock while we're
-  // stopping the thread on which it runs.
-  sink_->Stop();
 }
 
 void WebRtcAudioRenderer::SetVolume(float volume) {