Update platform classes to use OVERRIDE / FINAL when needed

Source/platform/fonts/SegmentedFontData.h

 /*
  * Copyright (C) 2008, 2009 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 46 matching lines @@
 public:
     static PassRefPtr<SegmentedFontData> create() { return adoptRef(new SegmentedFontData); }
 
     virtual ~SegmentedFontData();
 
     void appendRange(const FontDataRange& range) { m_ranges.append(range); }
     unsigned numRanges() const { return m_ranges.size(); }
     const FontDataRange& rangeAt(unsigned i) const { return m_ranges[i]; }
 
 #ifndef NDEBUG
-    virtual String description() const;
+    virtual String description() const OVERRIDE;
 #endif
 
 private:
     SegmentedFontData() { }
 
     virtual const SimpleFontData* fontDataForCharacter(UChar32) const OVERRIDE;
     virtual bool containsCharacters(const UChar*, int length) const OVERRIDE;
 
     virtual bool isCustomFont() const OVERRIDE;
     virtual bool isLoading() const OVERRIDE;
     virtual bool isLoadingFallback() const OVERRIDE;
     virtual bool isSegmented() const OVERRIDE;
 
     bool containsCharacter(UChar32) const;
 
     Vector<FontDataRange, 1> m_ranges;
 };
 
 DEFINE_TYPE_CASTS(SegmentedFontData, FontData, fontData, fontData->isSegmented(), fontData.isSegmented());
 
 } // namespace WebCore
 
 #endif // SegmentedFontData_h