Count 'icon' attribute of MENUITEM element.

third_party/WebKit/Source/core/html/HTMLUnknownElement.h

 /*
  * Copyright (c) 2011 Code Aurora Forum. 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
  *       copyright notice, this list of conditions and the following
@@ skipping 28 matching lines @@
 
  public:
   static HTMLUnknownElement* create(const QualifiedName& tagName,
                                     Document& document) {
     return new HTMLUnknownElement(tagName, document);
   }
 
  private:
   HTMLUnknownElement(const QualifiedName&, Document&);
 
+  void parseAttribute(const AttributeModificationParams&) override;
   bool isHTMLUnknownElement() const override { return true; }
 };
 
 inline bool isHTMLUnknownElement(const HTMLElement& element) {
   return element.isHTMLUnknownElement();
 }
 
 DEFINE_HTMLELEMENT_TYPE_CASTS_WITH_FUNCTION(HTMLUnknownElement);
 
 }  // namespace blink
 
 #endif  // HTMLUnknownElement_h