Remove the AudioManager singleton.

media/audio/audio_output_proxy.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_STREAM_PROXY_H_
-#define MEDIA_AUDIO_AUDIO_OUTPUT_STREAM_PROXY_H_
+#ifndef MEDIA_AUDIO_AUDIO_OUTPUT_PROXY_H_
+#define MEDIA_AUDIO_AUDIO_OUTPUT_PROXY_H_
 
 #include "base/basictypes.h"
 #include "base/task.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_parameters.h"
 
 class AudioOutputDispatcher;
 
 // AudioOutputProxy is an audio otput stream that uses resources more
 // efficiently than a regular audio output stream: it opens audio
 // device only when sound is playing, i.e. between Start() and Stop()
 // (there is still one physical stream per each audio output proxy in
 // playing state).
 //
 // AudioOutputProxy uses AudioOutputDispatcher to open and close
 // physical output streams.
 class MEDIA_EXPORT AudioOutputProxy : public AudioOutputStream {
  public:
   // Caller keeps ownership of |dispatcher|.
-  AudioOutputProxy(AudioOutputDispatcher* dispatcher);
+  explicit AudioOutputProxy(AudioOutputDispatcher* dispatcher);
 
   // AudioOutputStream interface.
   virtual bool Open() OVERRIDE;
   virtual void Start(AudioSourceCallback* callback) OVERRIDE;
   virtual void Stop() OVERRIDE;
   virtual void SetVolume(double volume) OVERRIDE;
   virtual void GetVolume(double* volume) OVERRIDE;
   virtual void Close() OVERRIDE;
 
  private:
-  // Needs to access destructor.
-  friend class DeleteTask<AudioOutputProxy>;
-
   enum State {
     kCreated,
     kOpened,
     kPlaying,
     kClosed,
     kError,
   };
 
   virtual ~AudioOutputProxy();
 
   scoped_refptr<AudioOutputDispatcher> dispatcher_;
   State state_;
 
   // The actual audio stream. Must be set to NULL in any state other
   // than kPlaying.
   AudioOutputStream* physical_stream_;
 
   // Need to save volume here, so that we can restore it in case the stream
   // is stopped, and then started again.
   double volume_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioOutputProxy);
 };
 
-#endif  // MEDIA_AUDIO_AUDIO_OUTPUT_STREAM_PROXY_H_
+#endif  // MEDIA_AUDIO_AUDIO_OUTPUT_PROXY_H_