chromeos: Cleanup class/struct fwd declarations

chromeos/audio/cras_audio_handler.h

 // Copyright (c) 2013 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 CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_
 #define CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 #include <queue>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/timer/timer.h"
 #include "chromeos/audio/audio_device.h"
 #include "chromeos/audio/audio_devices_pref_handler.h"
 #include "chromeos/audio/audio_pref_observer.h"
 #include "chromeos/dbus/audio_node.h"
 #include "chromeos/dbus/cras_audio_client.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "chromeos/dbus/volume_state.h"
 
-class PrefRegistrySimple;
-class PrefService;
-
 namespace chromeos {
 
 class AudioDevicesPrefHandler;
 
 class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
                                          public AudioPrefObserver,
                                          public SessionManagerClient::Observer {
  public:
   typedef std::priority_queue<AudioDevice,
                               std::vector<AudioDevice>,
@@ skipping 426 matching lines @@
   uint64_t init_node_id_;
 
   base::WeakPtrFactory<CrasAudioHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CrasAudioHandler);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_