Pass task runners to AudioManager constructor.

media/audio/mac/audio_manager_mac.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_AUDIO_MAC_AUDIO_MANAGER_MAC_H_
 #define MEDIA_AUDIO_MAC_AUDIO_MANAGER_MAC_H_
 
 #include <AudioUnit/AudioUnit.h>
 #include <CoreAudio/AudioHardware.h>
 #include <stddef.h>
 #include <list>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "media/audio/audio_manager_base.h"
 #include "media/audio/mac/audio_device_listener_mac.h"
 
 namespace media {
 
 class AUAudioInputStream;
 class AUHALStream;
 
 // Mac OS X implementation of the AudioManager singleton. This class is internal
 // to the audio output and only internal users can call methods not exposed by
 // 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;
   void GetAudioOutputDeviceNames(AudioDeviceNames* device_names) override;
   AudioParameters GetInputStreamParameters(
       const std::string& device_id) override;
   std::string GetAssociatedOutputDeviceID(
       const std::string& input_device_id) override;
 
   // Implementation of AudioManagerBase.
@@ skipping 66 matching lines @@
 
  protected:
   ~AudioManagerMac() override;
 
   AudioParameters GetPreferredOutputStreamParameters(
       const std::string& output_device_id,
       const AudioParameters& input_params) override;
 
  private:
   void InitializeOnAudioThread();
-  void ShutdownOnAudioThread();
 
   int ChooseBufferSize(bool is_input, int sample_rate);
 
   // Notify streams of a device change if the default output device or its
   // sample rate has changed, otherwise does nothing.
   void HandleDeviceChanges();
 
   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_;
   AudioDeviceID current_output_device_;
 
   // Helper class which monitors power events to determine if output streams
   // should defer Start() calls.  Required to workaround an OSX bug.  See
   // http://crbug.com/160920 for more details.
   class AudioPowerObserver;
   scoped_ptr<AudioPowerObserver> power_observer_;
 
-  // Tracks all constructed input and output streams so they can be stopped at
-  // shutdown.  See ShutdownOnAudioThread() for more details.
+  // Tracks all constructed input and output streams.
+  // TODO(alokp): We used to track these streams to close before destruction.

[DaleCurtis, 2016/04/14 00:00:35]

Delete these? You already removed the stop streams code. If you can't remove
them then you can't land this CL as is right? I.e. it would imply that all other
platforms will now have the same issue as OSX.

[alokp, 2016/04/14 13:30:03]

Sorry I do not understand your comment. Remove the TODO or the member variables?
The member variables are still being used by MaybeChangeBufferSize().

+  // We no longer close the streams, so we may be able to get rid of these
+  // member variables. They are currently used by MaybeChangeBufferSize().
+  // Investigate if we can remove these.
   std::list<AudioInputStream*> basic_input_streams_;
   std::list<AUAudioInputStream*> low_latency_input_streams_;
   std::list<AUHALStream*> output_streams_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioManagerMac);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_MAC_AUDIO_MANAGER_MAC_H_