Update modules classes to use OVERRIDE / FINAL when needed

Source/modules/webaudio/OfflineAudioCompletionEvent.h

Index: Source/modules/webaudio/OfflineAudioCompletionEvent.h
diff --git a/Source/modules/webaudio/OfflineAudioCompletionEvent.h b/Source/modules/webaudio/OfflineAudioCompletionEvent.h
index c994c628a714a84b3c8e047e0c7a2ae63c972c93..9066630872206b963b9335c009d32036e6823efb 100644
--- a/Source/modules/webaudio/OfflineAudioCompletionEvent.h
+++ b/Source/modules/webaudio/OfflineAudioCompletionEvent.h
@@ -34,7 +34,7 @@ namespace WebCore {
 
 class AudioBuffer;
 
-class OfflineAudioCompletionEvent : public Event {
+class OfflineAudioCompletionEvent FINAL : public Event {
 public:
     static PassRefPtr<OfflineAudioCompletionEvent> create();
     static PassRefPtr<OfflineAudioCompletionEvent> create(PassRefPtr<AudioBuffer> renderedBuffer);
@@ -43,7 +43,7 @@ public:
 
     AudioBuffer* renderedBuffer() { return m_renderedBuffer.get(); }
 
-    virtual const AtomicString& interfaceName() const;
+    virtual const AtomicString& interfaceName() const OVERRIDE;
 
 private:
     OfflineAudioCompletionEvent();