Fix virtual/override/final usage in Source/core/html/.

Source/core/html/HTMLTemplateElement.h

 /*
  * Copyright (c) 2012, Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 24 matching lines @@
 
 namespace blink {
 
 class DocumentFragment;
 class TemplateContentDocumentFragment;
 
 class HTMLTemplateElement final : public HTMLElement {
     DEFINE_WRAPPERTYPEINFO();
 public:
     DECLARE_NODE_FACTORY(HTMLTemplateElement);
-    virtual ~HTMLTemplateElement();
+    ~HTMLTemplateElement() override;
     DECLARE_VIRTUAL_TRACE();
 
     DocumentFragment* content() const;
 
 private:
-    virtual PassRefPtrWillBeRawPtr<Node> cloneNode(bool deep = true) override;
-    virtual void didMoveToNewDocument(Document& oldDocument) override;
+    PassRefPtrWillBeRawPtr<Node> cloneNode(bool deep = true) override;
+    void didMoveToNewDocument(Document& oldDocument) override;
 
     explicit HTMLTemplateElement(Document&);
 
     mutable RefPtrWillBeMember<TemplateContentDocumentFragment> m_content;
 };
 
 } // namespace blink
 
 #endif // HTMLTemplateElement_h