Update remaining core classes to use OVERRIDE / FINAL when needed

Source/core/timing/PerformanceTiming.h

 /*
  * Copyright (C) 2010 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 26 matching lines @@
 #include "wtf/RefCounted.h"
 
 namespace WebCore {
 
 class DocumentLoadTiming;
 class DocumentLoader;
 struct DocumentTiming;
 class Frame;
 class ResourceLoadTiming;
 
-class PerformanceTiming : public RefCounted<PerformanceTiming>, public ScriptWrappable, public DOMWindowProperty {
+class PerformanceTiming FINAL : public RefCounted<PerformanceTiming>, public ScriptWrappable, public DOMWindowProperty {
 public:
     static PassRefPtr<PerformanceTiming> create(Frame* frame) { return adoptRef(new PerformanceTiming(frame)); }
 
     unsigned long long navigationStart() const;
     unsigned long long unloadEventStart() const;
     unsigned long long unloadEventEnd() const;
     unsigned long long redirectStart() const;
     unsigned long long redirectEnd() const;
     unsigned long long fetchStart() const;
     unsigned long long domainLookupStart() const;
@@ skipping 19 matching lines @@
     DocumentLoader* documentLoader() const;
     DocumentLoadTiming* documentLoadTiming() const;
     ResourceLoadTiming* resourceLoadTiming() const;
 
     unsigned long long monotonicTimeToIntegerMilliseconds(double) const;
 };
 
 }
 
 #endif // !defined(PerformanceTiming_h)