Update Event classes to use OVERRIDE / FINAL when needed

Source/core/events/CompositionEvent.h

Index: Source/core/events/CompositionEvent.h
diff --git a/Source/core/events/CompositionEvent.h b/Source/core/events/CompositionEvent.h
index f5c7284a46df445e7d6bfd10ba3af3840c94fc23..c3e0323c4118e57a5c1694db000acc193a695adc 100644
--- a/Source/core/events/CompositionEvent.h
+++ b/Source/core/events/CompositionEvent.h
@@ -38,7 +38,7 @@ struct CompositionEventInit : UIEventInit {
     String data;
 };
 
-class CompositionEvent : public UIEvent {
+class CompositionEvent FINAL : public UIEvent {
 public:
     static PassRefPtr<CompositionEvent> create()
     {
@@ -69,7 +69,7 @@ public:
     int activeSegmentEnd() const { return m_activeSegmentEnd; }
     const Vector<unsigned>& getSegments() const { return m_segments; }
 
-    virtual const AtomicString& interfaceName() const;
+    virtual const AtomicString& interfaceName() const OVERRIDE;
 
 private:
     CompositionEvent();