Count 'icon' attribute of MENUITEM element.

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

 // Copyright 2016 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.
 
 #include "core/html/HTMLUnknownElement.h"
 
 #include "core/frame/UseCounter.h"
 
 namespace blink {
 
 HTMLUnknownElement::HTMLUnknownElement(const QualifiedName& tagName,
                                        Document& document)
     : HTMLElement(tagName, document) {
   if (tagName.localName() == "data")
     UseCounter::count(document, UseCounter::DataElement);
   else if (tagName.localName() == "time")
     UseCounter::count(document, UseCounter::TimeElement);
   else if (tagName.localName() == "menuitem")
     UseCounter::count(document, UseCounter::MenuItemElement);
 }
 
+void HTMLUnknownElement::parseAttribute(
+    const AttributeModificationParams& params) {
+  if (params.name == HTMLNames::iconAttr && hasTagName(HTMLNames::menuitemTag))
+    UseCounter::count(document(), UseCounter::MenuItemElementIconAttribute);
+  HTMLElement::parseAttribute(params);
+}
+
 }  // namespace blink