Don't start WASAPI render thread until setup completes.

media/audio/win/audio_low_latency_output_win.h

Index: media/audio/win/audio_low_latency_output_win.h
diff --git a/media/audio/win/audio_low_latency_output_win.h b/media/audio/win/audio_low_latency_output_win.h
index 4efc0f6d9b31270c6fd352f00b9792dde0e13ce6..ac33fa683a551f0818d18d4dba66a52da8372611 100644
--- a/media/audio/win/audio_low_latency_output_win.h
+++ b/media/audio/win/audio_low_latency_output_win.h
@@ -157,7 +157,7 @@ class MEDIA_EXPORT WASAPIAudioOutputStream :
   // Checks available amount of space in the endpoint buffer and reads
   // data from the client to fill up the buffer without causing audio
   // glitches.
-  bool RenderAudioFromSource(IAudioClock* audio_clock, UINT64 device_frequency);
+  bool RenderAudioFromSource(UINT64 device_frequency);
 
   // Called when the device will be opened in exclusive mode and use the
   // application specified format.
@@ -250,6 +250,8 @@ class MEDIA_EXPORT WASAPIAudioOutputStream :
   // Container for retrieving data from AudioSourceCallback::OnMoreData().
   scoped_ptr<AudioBus> audio_bus_;
 
+  base::win::ScopedComPtr<IAudioClock> audio_clock_;
+
   DISALLOW_COPY_AND_ASSIGN(WASAPIAudioOutputStream);
 };