chrome: Cleanup class/struct forward declarations

chrome/browser/ui/views/frame/browser_header_painter_ash.h

 // Copyright 2014 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 CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_HEADER_PAINTER_ASH_H_
 #define CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_HEADER_PAINTER_ASH_H_
 
 #include <memory>
 
 #include "ash/common/frame/header_painter.h"
 #include "base/compiler_specific.h"  // override
 #include "base/macros.h"
 #include "ui/gfx/animation/animation_delegate.h"
 
 class BrowserNonClientFrameViewAsh;
 class BrowserView;
 
 namespace ash {
 class FrameCaptionButtonContainerView;
 }
 
 namespace gfx {
-class ImageSkia;
 class Rect;
 class SlideAnimation;
 }
 namespace views {
 class View;
 class Widget;
 }
 
 // Helper class for painting the browser window header.
 class BrowserHeaderPainterAsh : public ash::HeaderPainter,
@@ skipping 61 matching lines @@
 
   // Whether the header should be painted as active.
   Mode mode_;
 
   std::unique_ptr<gfx::SlideAnimation> activation_animation_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserHeaderPainterAsh);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_HEADER_PAINTER_ASH_H_