Cleanup remaining class/struct fwd declarations

apps/ui/views/app_window_frame_view.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 APPS_UI_VIEWS_APP_WINDOW_FRAME_VIEW_H_
 #define APPS_UI_VIEWS_APP_WINDOW_FRAME_VIEW_H_
 
 #include <string>
 
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/path.h"
 #include "ui/views/controls/button/button.h"
 #include "ui/views/window/non_client_view.h"
 
-class SkRegion;
-
 namespace extensions {
 class NativeAppWindow;
 }
 
 namespace gfx {
 class Canvas;
 class Point;
 }
 
 namespace ui {
@@ skipping 85 matching lines @@
 
   // Size in pixels of the lower-right corner resize handle.
   int resize_area_corner_size_;
 
   DISALLOW_COPY_AND_ASSIGN(AppWindowFrameView);
 };
 
 }  // namespace apps
 
 #endif  // APPS_UI_VIEWS_APP_WINDOW_FRAME_VIEW_H_