Count 'icon' attribute of MENUITEM element.

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef HTMLMenuItemElement_h
 #define HTMLMenuItemElement_h
 
 #include "core/html/HTMLElement.h"
 
 namespace blink {
 
 class HTMLMenuItemElement final : public HTMLElement {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
   DECLARE_NODE_FACTORY(HTMLMenuItemElement);
 
  private:
   explicit HTMLMenuItemElement(Document&);
   bool isURLAttribute(const Attribute&) const override;
+  void parseAttribute(const AttributeModificationParams&) override;
   void defaultEventHandler(Event*) override;
 };
 
 }  // namespace blink
 
 #endif  // HTMLMenuItemElement_h