Detect errors in audio output and report them upstream.

media/base/audio_renderer_sink.h

Index: media/base/audio_renderer_sink.h
diff --git a/media/base/audio_renderer_sink.h b/media/base/audio_renderer_sink.h
index 5888c6bee47f35f974c003902b9ebb70a7123784..57373a21c7d4f53fe05294a7d0db069f15e7e8ce 100644
--- a/media/base/audio_renderer_sink.h
+++ b/media/base/audio_renderer_sink.h
@@ -32,6 +32,9 @@ class AudioRendererSink
                           size_t number_of_frames,
                           size_t audio_delay_milliseconds) = 0;
 
+    // Signals an error has occurred.
+    virtual void OnError() = 0;
+
    protected:
     virtual ~RenderCallback() {}
   };