Update XML classes to use OVERRIDE / FINAL when needed

Source/core/xml/XSLStyleSheet.h

 /*
  * This file is part of the XSL implementation.
  *
  * Copyright (C) 2004, 2006, 2008, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 18 matching lines @@
 #include "wtf/PassRefPtr.h"
 
 #include <libxml/tree.h>
 #include <libxslt/transform.h>
 
 namespace WebCore {
 
 class ResourceFetcher;
 class XSLImportRule;
 
-class XSLStyleSheet : public StyleSheet {
+class XSLStyleSheet FINAL : public StyleSheet {
 public:
     static PassRefPtr<XSLStyleSheet> create(XSLImportRule* parentImport, const String& originalURL, const KURL& finalURL)
     {
         ASSERT(RuntimeEnabledFeatures::xsltEnabled());
         return adoptRef(new XSLStyleSheet(parentImport, originalURL, finalURL));
     }
     static PassRefPtr<XSLStyleSheet> create(ProcessingInstruction* parentNode, const String& originalURL, const KURL& finalURL)
     {
         ASSERT(RuntimeEnabledFeatures::xsltEnabled());
         return adoptRef(new XSLStyleSheet(parentNode, originalURL, finalURL, false));
@@ skipping 68 matching lines @@
     bool m_compilationFailed;
 
     XSLStyleSheet* m_parentStyleSheet;
 };
 
 DEFINE_TYPE_CASTS(XSLStyleSheet, StyleSheet, sheet, !sheet->isCSSStyleSheet(), !sheet.isCSSStyleSheet());
 
 } // namespace WebCore
 
 #endif // XSLStyleSheet_h