content: Cleanup class/struct forward declarations

content/browser/renderer_host/media/audio_input_renderer_host.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.
 //
 // AudioInputRendererHost serves audio related requests from audio capturer
 // which lives inside the render process and provide access to audio hardware.
 //
 // Create stream sequence (AudioInputController = AIC):
 //
 // AudioInputHostMsg_CreateStream -> OnCreateStream -> AIC::CreateLowLatency ->
@@ skipping 28 matching lines @@
 #include "content/common/media/audio_messages.h"
 #include "content/public/browser/browser_message_filter.h"
 #include "content/public/browser/browser_thread.h"
 #include "media/audio/audio_input_controller.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_logging.h"
 #include "media/audio/simple_sources.h"
 
 namespace media {
 class AudioManager;
-class AudioParameters;
 class UserInputMonitor;
 }
 
 namespace content {
 class AudioMirroringManager;
 class MediaStreamManager;
 class RenderProcessHost;
 
 class CONTENT_EXPORT AudioInputRendererHost
     : public BrowserMessageFilter,
@@ skipping 202 matching lines @@
   std::unique_ptr<media::AudioLog> audio_log_;
 
   base::WeakPtrFactory<AudioInputRendererHost> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioInputRendererHost);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_INPUT_RENDERER_HOST_H_