Update platform classes to use OVERRIDE / FINAL when needed

Source/platform/testing/ArenaTestHelpers.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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 19 matching lines @@
 #include "wtf/NotFound.h"
 #include "wtf/Vector.h"
 
 #include <gtest/gtest.h>
 
 namespace WebCore {
 namespace ArenaTestHelpers {
 
 // An allocator for the PODArena which tracks the regions which have
 // been allocated.
-class TrackedAllocator : public PODArena::FastMallocAllocator {
+class TrackedAllocator FINAL : public PODArena::FastMallocAllocator {
 public:
     static PassRefPtr<TrackedAllocator> create()
     {
         return adoptRef(new TrackedAllocator);
     }
 
-    virtual void* allocate(size_t size)
+    virtual void* allocate(size_t size) OVERRIDE
     {
         void* result = PODArena::FastMallocAllocator::allocate(size);
         m_allocatedRegions.append(result);
         return result;
     }
 
-    virtual void free(void* ptr)
+    virtual void free(void* ptr) OVERRIDE
     {
         size_t slot = m_allocatedRegions.find(ptr);
         ASSERT_NE(slot, kNotFound);
         m_allocatedRegions.remove(slot);
         PODArena::FastMallocAllocator::free(ptr);
     }
 
     bool isEmpty() const
     {
         return !numRegions();
     }
 
     int numRegions() const
     {
         return m_allocatedRegions.size();
     }
 
 private:
     TrackedAllocator() { }
     Vector<void*> m_allocatedRegions;
 };
 
 } // namespace ArenaTestHelpers
 } // namespace WebCore
 
 #endif // ArenaTestHelpers_h