Update more core classes to use OVERRIDE / FINAL when needed

Source/core/rendering/RenderLayerCompositor.h

 /*
  * Copyright (C) 2009 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 43 matching lines @@
 // composited RenderLayers. It determines which RenderLayers
 // become compositing, and creates and maintains a hierarchy of
 // GraphicsLayers based on the RenderLayer painting order.
 //
 // There is one RenderLayerCompositor per RenderView.
 
 class RenderLayerCompositor FINAL : public GraphicsLayerClient {
     WTF_MAKE_FAST_ALLOCATED;
 public:
     explicit RenderLayerCompositor(RenderView*);
-    ~RenderLayerCompositor();
+    virtual ~RenderLayerCompositor();
 
     // Return true if this RenderView is in "compositing mode" (i.e. has one or more
     // composited RenderLayers)
     bool inCompositingMode() const { return m_compositing; }
     // This will make a compositing layer at the root automatically, and hook up to
     // the native view/window system.
     void enableCompositingMode(bool enable = true);
 
     bool inForcedCompositingMode() const { return m_forceCompositingMode; }
 
@@ skipping 293 matching lines @@
     OwnPtr<GraphicsLayer> m_layerForScrollCorner;
 #if USE(RUBBER_BANDING)
     OwnPtr<GraphicsLayer> m_layerForOverhangShadow;
 #endif
 };
 
 
 } // namespace WebCore
 
 #endif // RenderLayerCompositor_h