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

Source/wtf/text/TextCodecUTF8.h

Index: Source/wtf/text/TextCodecUTF8.h
diff --git a/Source/wtf/text/TextCodecUTF8.h b/Source/wtf/text/TextCodecUTF8.h
index 5a2359acb8d8c0cc18c7b8dc53ceb98ae72f0c66..feb5682a77ed860c088fa11c6f2d1ce8ef45ec16 100644
--- a/Source/wtf/text/TextCodecUTF8.h
+++ b/Source/wtf/text/TextCodecUTF8.h
@@ -41,9 +41,9 @@ protected:
 private:
     static PassOwnPtr<TextCodec> create(const TextEncoding&, const void*);
 
-    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* characters, size_t length);