Revert of Pass task runners to AudioManager constructor.

media/audio/audio_manager_base.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_AUDIO_MANAGER_BASE_H_
 #define MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
 
 #include <string>
 #include <utility>
 
@@ skipping 45 matching lines @@
   // device should be selected basing on |device_id|.
   // If |device_id| is empty and |session_id| is nonzero, output device
   // associated with the opened input device designated by |session_id| should
   // be used.
   static bool UseSessionIdToSelectDevice(int session_id,
                                          const std::string& device_id);
 
   ~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;
   void GetAudioOutputDeviceNames(AudioDeviceNames* device_names) override;
   AudioOutputStream* MakeAudioOutputStream(
       const AudioParameters& params,
       const std::string& device_id) override;
   AudioInputStream* MakeAudioInputStream(const AudioParameters& params,
                                          const std::string& device_id) override;
   AudioOutputStream* MakeAudioOutputStreamProxy(
@@ skipping 37 matching lines @@
 
   // Creates the input stream for the |AUDIO_PCM_LOW_LATENCY| format.
   virtual AudioInputStream* MakeLowLatencyInputStream(
       const AudioParameters& params, const std::string& device_id) = 0;
 
   // Get number of input or output streams.
   int input_stream_count() const { return num_input_streams_; }
   int output_stream_count() const { return num_output_streams_; }
 
  protected:
-  AudioManagerBase(
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
-      scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
-      AudioLogFactory* audio_log_factory);
+  AudioManagerBase(AudioLogFactory* audio_log_factory);
 
-  // Releases all the audio output dispatchers.
-  // All audio streams should be closed before Shutdown() is called.
-  // This must be called in the destructor of every AudioManagerBase
+  // 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();
 
   void SetMaxOutputStreamsAllowed(int max) { max_num_output_streams_ = max; }
 
   // Called by each platform specific AudioManager to notify output state change
   // listeners that a state change has occurred.  Must be called from the audio
   // thread.
   void NotifyAllOutputDeviceChangeListeners();
 
@@ skipping 15 matching lines @@
   // Returns the ID of the default audio output device.
   // Implementations that don't yet support this should return an empty string.
   virtual std::string GetDefaultOutputDeviceID();
 
  private:
   struct DispatcherParams;
   typedef ScopedVector<DispatcherParams> AudioOutputDispatchers;
 
   class CompareByParams;
 
+  // Called by Shutdown().
+  void ShutdownOnAudioThread();
+
   // Max number of open output streams, modified by
   // SetMaxOutputStreamsAllowed().
   int max_num_output_streams_;
 
   // Max number of open input streams.
   int max_num_input_streams_;
 
   // Number of currently open output streams.
   int num_output_streams_;
 
   // Number of currently open input streams.
   int num_input_streams_;
 
   // 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_;
 
   // Proxy for creating AudioLog objects.
   AudioLogFactory* const audio_log_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_