content: Cleanup class/struct forward declarations

content/browser/media/media_internals.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 CONTENT_BROWSER_MEDIA_MEDIA_INTERNALS_H_
 #define CONTENT_BROWSER_MEDIA_MEDIA_INTERNALS_H_
 
 #include <list>
 #include <map>
 #include <string>
 #include <tuple>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/compiler_specific.h"
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "base/synchronization/lock.h"
 #include "base/values.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "media/audio/audio_logging.h"
 #include "media/base/media_log.h"
 #include "media/capture/video/video_capture_device_descriptor.h"
 #include "media/capture/video_capture_types.h"
 
 namespace media {
-class AudioParameters;
 struct MediaLogEvent;
 }
 
 namespace content {
 
 // This class stores information about currently active media.
 class CONTENT_EXPORT MediaInternals
     : NON_EXPORTED_BASE(public media::AudioLogFactory),
       public NotificationObserver {
  public:
@@ skipping 98 matching lines @@
   base::DictionaryValue audio_streams_cached_data_;
   int owner_ids_[AUDIO_COMPONENT_MAX];
   std::unique_ptr<MediaInternalsUMAHandler> uma_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaInternals);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_MEDIA_INTERNALS_H_