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

Source/core/html/HTMLShadowElement.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 22 matching lines @@
 
 #include "core/dom/shadow/InsertionPoint.h"
 #include "wtf/Forward.h"
 
 namespace blink {
 
 class HTMLShadowElement final : public InsertionPoint {
     DEFINE_WRAPPERTYPEINFO();
 public:
     DECLARE_NODE_FACTORY(HTMLShadowElement);
-    virtual ~HTMLShadowElement();
+    ~HTMLShadowElement() override;
 
     ShadowRoot* olderShadowRoot();
 
 private:
     explicit HTMLShadowElement(Document&);
-    virtual InsertionNotificationRequest insertedInto(ContainerNode* insertionPoint) override;
+    InsertionNotificationRequest insertedInto(ContainerNode* insertionPoint) override;
 };
 
 } // namespace blink
 
 #endif // HTMLShadowElement_h