Pass task runners to AudioManager constructor.

chromecast/media/audio/cast_audio_manager.h

Index: chromecast/media/audio/cast_audio_manager.h
diff --git a/chromecast/media/audio/cast_audio_manager.h b/chromecast/media/audio/cast_audio_manager.h
index f2cec7e1d556e0ef6f00e8a4889812546af44d99..f4a201d78518272a24689914d683b3aaf455420c 100644
--- a/chromecast/media/audio/cast_audio_manager.h
+++ b/chromecast/media/audio/cast_audio_manager.h
@@ -19,7 +19,10 @@ struct MediaPipelineDeviceParams;
 
 class CastAudioManager : public ::media::AudioManagerBase {
  public:
-  explicit CastAudioManager(::media::AudioLogFactory* audio_log_factory);
+  CastAudioManager(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
+      ::media::AudioLogFactory* audio_log_factory);
   ~CastAudioManager() override;
 
   // AudioManager implementation.