Update rendering classes to use OVERRIDE / FINAL when needed

Source/core/rendering/RenderScrollbarPart.h

Index: Source/core/rendering/RenderScrollbarPart.h
diff --git a/Source/core/rendering/RenderScrollbarPart.h b/Source/core/rendering/RenderScrollbarPart.h
index 3dc713734d0bb361b33d39a1b661bb461b786c5e..fa6695ab9afc8b76846ce824653e0956989561d8 100644
--- a/Source/core/rendering/RenderScrollbarPart.h
+++ b/Source/core/rendering/RenderScrollbarPart.h
@@ -39,11 +39,11 @@ public:
 
     virtual ~RenderScrollbarPart();
 
-    virtual const char* renderName() const { return "RenderScrollbarPart"; }
+    virtual const char* renderName() const OVERRIDE { return "RenderScrollbarPart"; }
 
     virtual LayerType layerTypeRequired() const OVERRIDE { return NoLayer; }
 
-    virtual void layout();
+    virtual void layout() OVERRIDE;
 
     void paintIntoRect(GraphicsContext*, const LayoutPoint&, const LayoutRect&);
 
@@ -53,18 +53,18 @@ public:
     virtual LayoutUnit marginLeft() const OVERRIDE { ASSERT(isIntegerValue(m_marginBox.left())); return m_marginBox.left(); }
     virtual LayoutUnit marginRight() const OVERRIDE { ASSERT(isIntegerValue(m_marginBox.right())); return m_marginBox.right(); }
 
-    virtual bool isRenderScrollbarPart() const { return true; }
+    virtual bool isRenderScrollbarPart() const OVERRIDE { return true; }
     RenderObject* rendererOwningScrollbar() const;
 
 protected:
-    virtual void styleWillChange(StyleDifference diff, const RenderStyle* newStyle);
-    virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
-    virtual void imageChanged(WrappedImagePtr, const IntRect* = 0);
+    virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle) OVERRIDE;
+    virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE;
+    virtual void imageChanged(WrappedImagePtr, const IntRect* = 0) OVERRIDE;
 
 private:
     RenderScrollbarPart(RenderScrollbar*, ScrollbarPart);
 
-    virtual void computePreferredLogicalWidths();
+    virtual void computePreferredLogicalWidths() OVERRIDE;
 
     virtual bool supportsPartialLayout() const OVERRIDE { return false; }