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

Source/wtf/text/TextCodecICU.h

Index: Source/wtf/text/TextCodecICU.h
diff --git a/Source/wtf/text/TextCodecICU.h b/Source/wtf/text/TextCodecICU.h
index b3e6e8d7b6844e64c0720b52223c7cac30dafa9b..b6efcef096a244c0250a67e66b4ecbd4cade95e7 100644
--- a/Source/wtf/text/TextCodecICU.h
+++ b/Source/wtf/text/TextCodecICU.h
@@ -42,15 +42,15 @@ public:
     static void registerEncodingNames(EncodingNameRegistrar);
     static void registerCodecs(TextCodecRegistrar);
 
-    virtual ~TextCodecICU();
+    ~TextCodecICU() override;
 
 private:
     TextCodecICU(const TextEncoding&);
     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*, size_t length, UnencodableHandling);