Pass task runners to AudioManager constructor.

media/audio/mac/audio_manager_mac.h

Index: media/audio/mac/audio_manager_mac.h
diff --git a/media/audio/mac/audio_manager_mac.h b/media/audio/mac/audio_manager_mac.h
index 0545f43754be27d69f14c87b5bc212159d98051b..40354acf49e02244d711d22c82a26bbf476bdfdf 100644
--- a/media/audio/mac/audio_manager_mac.h
+++ b/media/audio/mac/audio_manager_mac.h
@@ -26,11 +26,12 @@ class AUHALStream;
 // the AudioManager class.
 class MEDIA_EXPORT AudioManagerMac : public AudioManagerBase {
  public:
-  AudioManagerMac(AudioLogFactory* audio_log_factory);
+  AudioManagerMac(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
+      AudioLogFactory* audio_log_factory);
 
   // Implementation of AudioManager.
-  scoped_refptr<base::SingleThreadTaskRunner> GetTaskRunner() override;
-  scoped_refptr<base::SingleThreadTaskRunner> GetWorkerTaskRunner() override;
   bool HasAudioOutputDevices() override;
   bool HasAudioInputDevices() override;
   void GetAudioInputDeviceNames(AudioDeviceNames* device_names) override;
@@ -124,9 +125,6 @@ class MEDIA_EXPORT AudioManagerMac : public AudioManagerBase {
 
   scoped_ptr<AudioDeviceListenerMac> output_device_listener_;
 
-  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
-  scoped_ptr<base::Thread> worker_thread_;
-
   // Track the output sample-rate and the default output device
   // so we can intelligently handle device notifications only when necessary.
   int current_sample_rate_;