Factor out AudioOutputDelegate from AudioRendererHost.

media/audio/audio_output_controller.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_OUTPUT_CONTROLLER_H_
 #define MEDIA_AUDIO_AUDIO_OUTPUT_CONTROLLER_H_
 
 #include <stdint.h>
 #include <memory>
 #include <set>
@@ skipping 53 matching lines @@
 class MEDIA_EXPORT AudioOutputController
     : public base::RefCountedThreadSafe<AudioOutputController>,
       public AudioOutputStream::AudioSourceCallback,
       public AudioSourceDiverter,
       NON_EXPORTED_BASE(public AudioManager::AudioDeviceListener)  {
  public:
   // An event handler that receives events from the AudioOutputController. The
   // following methods are called on the audio manager thread.
   class MEDIA_EXPORT EventHandler {
    public:
-    virtual void OnCreated() = 0;
-    virtual void OnPlaying() = 0;
-    virtual void OnPaused() = 0;
-    virtual void OnError() = 0;
+    virtual void OnControllerCreated() = 0;
+    virtual void OnControllerPlaying() = 0;
+    virtual void OnControllerPaused() = 0;
+    virtual void OnControllerError() = 0;
 
    protected:
     virtual ~EventHandler() {}
   };
 
   // A synchronous reader interface used by AudioOutputController for
   // synchronous reading.
   // TODO(crogers): find a better name for this class and the Read() method
   // now that it can handle synchronized I/O.
   class SyncReader {
@@ skipping 13 matching lines @@
     // be fulfilled (due to timeout).
     virtual void Read(AudioBus* dest) = 0;
 
     // Close this synchronous reader.
     virtual void Close() = 0;
   };
 
   // Factory method for creating an AudioOutputController.
   // This also creates and opens an AudioOutputStream on the audio manager
   // thread, and if this is successful, the |event_handler| will receive an
-  // OnCreated() call from the same audio manager thread.  |audio_manager| must
-  // outlive AudioOutputController.
+  // OnControllerCreated() call from the same audio manager thread.
+  // |audio_manager| must outlive AudioOutputController.
   // The |output_device_id| can be either empty (default device) or specify a
   // specific hardware device for audio output.
   static scoped_refptr<AudioOutputController> Create(
       AudioManager* audio_manager, EventHandler* event_handler,
       const AudioParameters& params, const std::string& output_device_id,
       SyncReader* sync_reader);
 
   // Indicates whether audio power level analysis will be performed.  If false,
   // ReadCurrentPowerAndClip() can not be called.
   static bool will_monitor_audio_levels() {
 #if defined(OS_ANDROID) || defined(OS_IOS)
     return false;
 #else
     return true;
 #endif
   }
 
   // Methods to control playback of the stream.
 
   // Starts the playback of this audio output stream.
   void Play();
 
   // Pause this audio output stream.
   void Pause();
 
   // Closes the audio output stream. The state is changed and the resources
-  // are freed on the audio manager thread. closed_task is executed after that.
-  // Callbacks (EventHandler and SyncReader) must exist until closed_task is
-  // called.
+  // are freed on the audio manager thread. |closed_task| is executed after
+  // that, on the thread on which Close was called. Callbacks (EventHandler and
+  // SyncReader) must exist until closed_task is called, but they are safe
+  // to delete after that.
   //
   // It is safe to call this method more than once. Calls after the first one
   // will have no effect.
   void Close(const base::Closure& closed_task);
 
   // Sets the volume of the audio output stream.
   void SetVolume(double volume);
 
   // Calls |callback| (on the caller's thread) with the current output
   // device ID.
@@ skipping 132 matching lines @@
   // be accessed while |error_lock_| is held.
   bool ignore_errors_during_stop_close_;
   base::Lock error_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioOutputController);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_OUTPUT_CONTROLLER_H_