ui: Cleanup class/struct forward declarations

ui/accelerated_widget_mac/accelerated_widget_mac.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 UI_ACCELERATED_WIDGET_MAC_ACCELERATED_WIDGET_MAC_H_
 #define UI_ACCELERATED_WIDGET_MAC_ACCELERATED_WIDGET_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 #include <IOSurface/IOSurface.h>
 #include <vector>
 
 #include "base/mac/scoped_cftyperef.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "ui/accelerated_widget_mac/accelerated_widget_mac_export.h"
 #include "ui/base/cocoa/remote_layer_api.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/native_widget_types.h"
 
-class SkCanvas;
-
-namespace cc {
-class SoftwareFrameData;
-}
-
 namespace ui {
 
 class FullscreenLowPowerCoordinator;
 
 // A class through which an AcceleratedWidget may be bound to draw the contents
 // of an NSView. An AcceleratedWidget may be bound to multiple different views
 // throughout its lifetime (one at a time, though).
 class AcceleratedWidgetMacNSView {
  public:
   virtual NSView* AcceleratedWidgetGetNSView() const = 0;
@@ skipping 74 matching lines @@
 
   // The size in DIP of the last swap received from |compositor_|.
   gfx::Size last_swap_size_dip_;
 
   DISALLOW_COPY_AND_ASSIGN(AcceleratedWidgetMac);
 };
 
 }  // namespace ui
 
 #endif  // UI_ACCELERATED_WIDGET_MAC_ACCELERATED_WIDGET_MAC_H_