Pass task runners to AudioManager constructor.

media/audio/audio_manager_base.h

Index: media/audio/audio_manager_base.h
diff --git a/media/audio/audio_manager_base.h b/media/audio/audio_manager_base.h
index 2a926904fd488e36db747da7019689f964f97436..40cfd7077dee251d182cf3012b0c45f4fda5be2a 100644
--- a/media/audio/audio_manager_base.h
+++ b/media/audio/audio_manager_base.h
@@ -52,8 +52,6 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   ~AudioManagerBase() override;
 
   // AudioManager:
-  scoped_refptr<base::SingleThreadTaskRunner> GetTaskRunner() override;
-  scoped_refptr<base::SingleThreadTaskRunner> GetWorkerTaskRunner() override;
   base::string16 GetAudioInputDeviceModel() override;
   void ShowAudioInputSettings() override;
   void GetAudioInputDeviceNames(AudioDeviceNames* device_names) override;
@@ -111,13 +109,10 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   int output_stream_count() const { return num_output_streams_; }
 
  protected:
-  AudioManagerBase(AudioLogFactory* audio_log_factory);
-
-  // Shuts down the audio thread and releases all the audio output dispatchers
-  // on the audio thread.  All audio streams should be freed before Shutdown()
-  // is called.  This must be called in the destructor of every AudioManagerBase
-  // implementation.
-  void Shutdown();
+  AudioManagerBase(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
+      AudioLogFactory* audio_log_factory);
 
   void SetMaxOutputStreamsAllowed(int max) { max_num_output_streams_ = max; }
 
@@ -151,9 +146,6 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
 
   class CompareByParams;
 
-  // Called by Shutdown().
-  void ShutdownOnAudioThread();
-
   // Max number of open output streams, modified by
   // SetMaxOutputStreamsAllowed().
   int max_num_output_streams_;
@@ -170,9 +162,6 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   // Track output state change listeners.
   base::ObserverList<AudioDeviceListener> output_listeners_;
 
-  // Thread used to interact with audio streams created by this audio manager.
-  scoped_ptr<base::Thread> audio_thread_;
-
   // Map of cached AudioOutputDispatcher instances.  Must only be touched
   // from the audio thread (no locking).
   AudioOutputDispatchers output_dispatchers_;