Defer OSX output stream Start() around system supend and resume.

media/audio/mac/audio_auhal_mac.h

Index: media/audio/mac/audio_auhal_mac.h
diff --git a/media/audio/mac/audio_auhal_mac.h b/media/audio/mac/audio_auhal_mac.h
index b488b73c0d135e7047b882b76dc6aae3e8d3a633..5c697f58fa1f8a6316de32e1f55d445389909e63 100644
--- a/media/audio/mac/audio_auhal_mac.h
+++ b/media/audio/mac/audio_auhal_mac.h
@@ -20,6 +20,7 @@
 #include <AudioUnit/AudioUnit.h>
 #include <CoreAudio/CoreAudio.h>
 
+#include "base/cancelable_callback.h"
 #include "base/compiler_specific.h"
 #include "base/synchronization/lock.h"
 #include "media/audio/audio_io.h"
@@ -166,6 +167,9 @@ class AUHALStream : public AudioOutputStream {
   // Current buffer delay.  Set by Render().
   uint32 current_hardware_pending_bytes_;
 
+  // Used to defer Start() to workaround http://crbug.com/160920.
+  base::CancelableClosure deferred_start_cb_;
+
   DISALLOW_COPY_AND_ASSIGN(AUHALStream);
 };