Fix virtual/override/final usage in Source/wtf/.

Source/wtf/text/TextCodecUTF16.h

 /*
  * Copyright (C) 2004, 2006 Apple Computer, 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 19 matching lines @@
 
 namespace WTF {
 
     class TextCodecUTF16 final : public TextCodec {
     public:
         static void registerEncodingNames(EncodingNameRegistrar);
         static void registerCodecs(TextCodecRegistrar);
 
         TextCodecUTF16(bool littleEndian) : m_littleEndian(littleEndian), m_haveBufferedByte(false) { }
 
-        virtual String decode(const char*, size_t length, FlushBehavior, bool stopOnError, bool& sawError) override;
-        virtual CString encode(const UChar*, size_t length, UnencodableHandling) override;
-        virtual CString encode(const LChar*, size_t length, UnencodableHandling) override;
+        String decode(const char*, size_t length, FlushBehavior, bool stopOnError, bool& sawError) override;
+        CString encode(const UChar*, size_t length, UnencodableHandling) override;
+        CString encode(const LChar*, size_t length, UnencodableHandling) override;
 
     private:
         bool m_littleEndian;
         bool m_haveBufferedByte;
         unsigned char m_bufferedByte;
     };
 
 } // namespace WTF
 
 #endif // TextCodecUTF16_h