content: Cleanup class/struct forward declarations

content/browser/media/capture/desktop_capture_device_aura.h

 // Copyright 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 CONTENT_BROWSER_MEDIA_CAPTURE_DESKTOP_CAPTURE_DEVICE_AURA_H_
 #define CONTENT_BROWSER_MEDIA_CAPTURE_DESKTOP_CAPTURE_DEVICE_AURA_H_
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/desktop_media_id.h"
 #include "media/capture/content/screen_capture_device_core.h"
 #include "media/capture/video/video_capture_device.h"
 
-namespace aura {
-class Window;
-}  // namespace aura
-
 namespace content {
 
 // An implementation of VideoCaptureDevice that mirrors an Aura window.
 class CONTENT_EXPORT DesktopCaptureDeviceAura
     : public media::VideoCaptureDevice {
  public:
   // Creates a VideoCaptureDevice for the Aura desktop.  If |source| does not
   // reference a registered aura window, returns nullptr instead.
   static std::unique_ptr<media::VideoCaptureDevice> Create(
       const DesktopMediaID& source);
@@ skipping 11 matching lines @@
 
   std::unique_ptr<media::ScreenCaptureDeviceCore> core_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopCaptureDeviceAura);
 };
 
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_CAPTURE_DESKTOP_CAPTURE_DEVICE_AURA_H_