content: Cleanup class/struct forward declarations

content/public/browser/render_widget_host_view_frame_subscriber.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_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_FRAME_SUBSCRIBER_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_FRAME_SUBSCRIBER_H_
 
 #include "base/callback.h"
 #include "base/time/time.h"
 
 namespace gfx {
 class Rect;
-class Size;
 }  // namespace gfx
 
 namespace media {
 class VideoFrame;
 }  // namespace media
 
 namespace content {
 
 // Defines an interface for listening to events of frame presentation and to
 // instruct the platform layer (i.e. RenderWidgetHostView) to copy a frame.
@@ skipping 43 matching lines @@
   // Return false if the current frame should not be captured.
   virtual bool ShouldCaptureFrame(const gfx::Rect& damage_rect,
                                   base::TimeTicks present_time,
                                   scoped_refptr<media::VideoFrame>* storage,
                                   DeliverFrameCallback* callback) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_FRAME_SUBSCRIBER_H_