Remove the AudioManager singleton.

media/audio/audio_output_controller.h

 // Copyright (c) 2011 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 "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/time.h"
 #include "media/audio/audio_buffers_state.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_manager.h"
 #include "media/audio/simple_sources.h"
 
 class MessageLoop;
 
 // An AudioOutputController controls an AudioOutputStream and provides data
@@ skipping 87 matching lines @@
     virtual bool DataReady() = 0;
   };
 
   virtual ~AudioOutputController();
 
   // Factory method for creating an AudioOutputController.
   // If successful, an audio controller thread is created. The audio device
   // will be created on the audio controller thread and when that is done
   // event handler will receive a OnCreated() call.
   static scoped_refptr<AudioOutputController> Create(
+      AudioManager* audio_manager,
       EventHandler* event_handler,
       const AudioParameters& params,
       // Soft limit for buffer capacity in this controller. This parameter
       // is used only in regular latency mode.
       uint32 buffer_capacity);
 
   // Factory method for creating a low latency audio stream.
   static scoped_refptr<AudioOutputController> CreateLowLatency(
+      AudioManager* audio_manager,
       EventHandler* event_handler,
       const AudioParameters& params,
       // External synchronous reader for audio controller.
       SyncReader* sync_reader);
 
   // Methods to control playback of the stream.
 
   // Starts the playback of this audio output stream.
   void Play();
 
@@ skipping 43 matching lines @@
     kPaused,
     kClosed,
     kError,
   };
 
  private:
   // We are polling sync reader if data became available.
   static const int kPollNumAttempts;
   static const int kPollPauseInMilliseconds;
 
-  AudioOutputController(EventHandler* handler,
+  AudioOutputController(AudioManager* audio_manager,
+                        EventHandler* handler,
                         uint32 capacity, SyncReader* sync_reader);
 
   // The following methods are executed on the audio controller thread.
   void DoCreate(const AudioParameters& params);
   void DoPlay();
   void PollAndStartIfDataReady();
   void DoPause();
   void DoFlush();
   void DoClose(const base::Closure& closed_task);
   void DoSetVolume(double volume);
   void DoReportError(int code);
 
   // Helper method to submit a OnMoreData() call to the event handler.
   void SubmitOnMoreData_Locked();
 
   // Helper method that starts physical stream.
   void StartStream();
 
   // Helper method that stops, closes, and NULLs |*stream_|.
   void StopCloseAndClearStream();
 
+  scoped_refptr<AudioManager> audio_manager_;
   // |handler_| may be called only if |state_| is not kClosed.
   EventHandler* handler_;
   AudioOutputStream* stream_;
 
   // The current volume of the audio stream.
   double volume_;
 
   // |state_| is written on the audio controller thread and is read on the
   // hardware audio thread. These operations need to be locked. But lock
   // is not required for reading on the audio controller thread.
@@ skipping 11 matching lines @@
   // SyncReader is used only in low latency mode for synchronous reading.
   SyncReader* sync_reader_;
 
   // The message loop of audio thread that this object runs on.
   MessageLoop* message_loop_;
 
   // When starting stream we wait for data to become available.
   // Number of times left.
   int number_polling_attempts_left_;
 
+  // Used to post delayed tasks to ourselves that we can cancel.

[henrika (OOO until Aug 14), 2011/12/07 10:08:34]

Can you add some more details on why you had to introduce this pattern. It is
not obvious why it is required. Perhaps add some extended comments in this area
in the actual header?

[tommi (sloooow) - chröme, 2011/12/07 12:26:44]

Improved comment.

+  base::WeakPtrFactory<AudioOutputController> weak_this_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioOutputController);
 };
 
 }  // namespace media
 
-#endif  //  MEDIA_AUDIO_AUDIO_OUTPUT_CONTROLLER_H_
+#endif  // MEDIA_AUDIO_AUDIO_OUTPUT_CONTROLLER_H_