Use NullAudioSink in WebMediaPlayerImpl if the audio sink is not OK.

media/blink/webmediaplayer_impl.cc

Index: media/blink/webmediaplayer_impl.cc
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index cdebe7739579127cc1db0a4aadd49269324e37b7..b764b367bd37e1e3b0ee9445b25c3f3adae489d6 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -250,9 +250,12 @@ WebMediaPlayerImpl::WebMediaPlayerImpl(
   // TODO(xhwang): When we use an external Renderer, many methods won't work,
   // e.g. GetCurrentFrameFromCompositor(). See http://crbug.com/434861
 
-  // Use the null sink if no sink was provided.
+  // Use the null sink if no valid sink was provided.
   audio_source_provider_ = new WebAudioSourceProviderImpl(
-      params.audio_renderer_sink().get()
+      params.audio_renderer_sink().get() &&
+              params.audio_renderer_sink()
+                      ->GetOutputDeviceInfo()
+                      .device_status() == OUTPUT_DEVICE_STATUS_OK
           ? params.audio_renderer_sink()
           : new NullAudioSink(media_task_runner_));
 }