Update platform classes to use OVERRIDE / FINAL when needed

Source/platform/graphics/Canvas2DImageBufferSurface.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 19 matching lines @@
 
 #ifndef Canvas2DImageBufferSurface_h
 #define Canvas2DImageBufferSurface_h
 
 #include "platform/graphics/Canvas2DLayerBridge.h"
 #include "platform/graphics/ImageBufferSurface.h"
 
 namespace WebCore {
 
 // This shim necessary because ImageBufferSurfaces are not allowed to be RefCounted
-class Canvas2DImageBufferSurface : public ImageBufferSurface {
+class Canvas2DImageBufferSurface FINAL : public ImageBufferSurface {
 public:
     Canvas2DImageBufferSurface(const IntSize& size, OpacityMode opacityMode = NonOpaque, int msaaSampleCount = 1)
         : ImageBufferSurface(size, opacityMode)
         , m_layerBridge(Canvas2DLayerBridge::create(size, opacityMode, msaaSampleCount))
     {
         clear();
     }
 
     virtual ~Canvas2DImageBufferSurface()
     {
         if (m_layerBridge)
             m_layerBridge->beginDestruction();
     }
 
     // ImageBufferSurface implementation
     virtual void willUse() OVERRIDE { m_layerBridge->willUse(); }
     virtual SkCanvas* canvas() const OVERRIDE { return m_layerBridge->canvas(); }
     virtual bool isValid() const OVERRIDE { return m_layerBridge && m_layerBridge->isValid(); }
     virtual blink::WebLayer* layer() const OVERRIDE { return m_layerBridge->layer(); }
     virtual Platform3DObject getBackingTexture() const OVERRIDE { return m_layerBridge->getBackingTexture(); }
-    virtual bool isAccelerated() const { return m_layerBridge->isAccelerated(); }
+    virtual bool isAccelerated() const OVERRIDE { return m_layerBridge->isAccelerated(); }
 
 private:
     RefPtr<Canvas2DLayerBridge> m_layerBridge;
 };
 
 }
 
 #endif