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

Source/wtf/text/TextCodecUserDefined.h

Index: Source/wtf/text/TextCodecUserDefined.h
diff --git a/Source/wtf/text/TextCodecUserDefined.h b/Source/wtf/text/TextCodecUserDefined.h
index 4aeda2dd67248cfa548935caad8ae1da22307ca7..f53aaa08a46796d09804328e152a23a71d398909 100644
--- a/Source/wtf/text/TextCodecUserDefined.h
+++ b/Source/wtf/text/TextCodecUserDefined.h
@@ -36,9 +36,9 @@ namespace WTF {
         static void registerCodecs(TextCodecRegistrar);
 
     private:
-        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;
 
         template<typename CharType>
         CString encodeCommon(const CharType*, size_t length, UnencodableHandling);