Update rendering classes to use OVERRIDE / FINAL when needed

Source/core/rendering/RenderFullScreen.h

Index: Source/core/rendering/RenderFullScreen.h
diff --git a/Source/core/rendering/RenderFullScreen.h b/Source/core/rendering/RenderFullScreen.h
index adbad3b4716015a45d4d10584ed3b413eca3617b..285dbd21a70bb6d039efcec2e58f1f54fe0ecd9c 100644
--- a/Source/core/rendering/RenderFullScreen.h
+++ b/Source/core/rendering/RenderFullScreen.h
@@ -34,8 +34,8 @@ class RenderFullScreen FINAL : public RenderFlexibleBox {
 public:
     static RenderFullScreen* createAnonymous(Document*);
 
-    virtual bool isRenderFullScreen() const { return true; }
-    virtual const char* renderName() const { return "RenderFullScreen"; }
+    virtual bool isRenderFullScreen() const OVERRIDE { return true; }
+    virtual const char* renderName() const OVERRIDE { return "RenderFullScreen"; }
 
     void setPlaceholder(RenderBlock*);
     RenderBlock* placeholder() { return m_placeholder; }
@@ -47,7 +47,7 @@ public:
 
 private:
     RenderFullScreen();
-    virtual void willBeDestroyed();
+    virtual void willBeDestroyed() OVERRIDE;
 
 protected:
     RenderBlock* m_placeholder;