Remove the AudioManager singleton.

media/audio/linux/audio_manager_linux.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_LINUX_AUDIO_MANAGER_LINUX_H_
 #define MEDIA_AUDIO_LINUX_AUDIO_MANAGER_LINUX_H_
 
-#include <set>
-
+#include <string>
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/threading/thread.h"
 #include "media/audio/audio_manager_base.h"
 
 class AlsaWrapper;
 
 class MEDIA_EXPORT AudioManagerLinux : public AudioManagerBase {
  public:
   AudioManagerLinux();
@@ skipping 34 matching lines @@
   void GetAlsaDevicesInfo(void** hint, media::AudioDeviceNames* device_names);
 
   // Checks if the specific ALSA device is available.
   bool IsAlsaDeviceAvailable(const char* device_name);
 
   // Returns true if a device is present for the given stream type.
   bool HasAnyAlsaAudioDevice(StreamType stream);
 
   scoped_ptr<AlsaWrapper> wrapper_;
 
-  std::set<AudioOutputStream*> active_streams_;
+  size_t active_output_stream_count_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioManagerLinux);
 };
 
 #endif  // MEDIA_AUDIO_LINUX_AUDIO_MANAGER_LINUX_H_