Replacing the OVERRIDE with override in third_party/WebKit/Source/platform

Source/platform/scroll/ScrollbarThemeOverlayMock.h

 /*
  * Copyright (C) 2013 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 22 matching lines @@
 
 #include "platform/scroll/ScrollbarThemeOverlay.h"
 
 namespace blink {
 
 class PLATFORM_EXPORT ScrollbarThemeOverlayMock : public ScrollbarThemeOverlay {
 public:
     ScrollbarThemeOverlayMock() : ScrollbarThemeOverlay(3, 4, DisallowHitTest, Color(128, 128, 128)) { }
 
 private:
-    virtual bool isMockTheme() const OVERRIDE FINAL { return true; }
+    virtual bool isMockTheme() const override FINAL { return true; }
 };
 
 } // namespace blink
 #endif // ScrollbarThemeOverlayMock_h