DevTools: migrate elements panel gutter icon to UI.Icon

third_party/WebKit/Source/devtools/front_end/elements/ElementsTreeElement.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2008 Matt Lilek <webkit@mattlilek.com>
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
@@ skipping 25 matching lines @@
    * @param {!SDK.DOMNode} node
    * @param {boolean=} elementCloseTag
    */
   constructor(node, elementCloseTag) {
     // The title will be updated in onattach.
     super();
     this._node = node;
 
     this._gutterContainer = this.listItemElement.createChild('div', 'gutter-container');
     this._gutterContainer.addEventListener('click', this._showContextMenu.bind(this));
+    var gutterMenuIcon = UI.Icon.create('largeicon-menu', 'gutter-menu-icon');
+    this._gutterContainer.appendChild(gutterMenuIcon);
     this._decorationsElement = this._gutterContainer.createChild('div', 'hidden');
 
     this._elementCloseTag = elementCloseTag;
 
     if (this._node.nodeType() === Node.ELEMENT_NODE && !elementCloseTag)
       this._canAddAttributes = true;
     this._searchQuery = null;
     this._expandedChildrenLimit = Elements.ElementsTreeElement.InitialChildrenLimit;
   }
 
@@ skipping 1507 matching lines @@
 
 // A union of HTML4 and HTML5-Draft elements that explicitly
 // or implicitly (for HTML5) forbid the closing tag.
 Elements.ElementsTreeElement.ForbiddenClosingTagElements = new Set([
   'area', 'base',  'basefont', 'br',   'canvas',   'col',  'command', 'embed',  'frame', 'hr',
   'img',  'input', 'keygen',   'link', 'menuitem', 'meta', 'param',   'source', 'track', 'wbr'
 ]);
 
 // These tags we do not allow editing their tag name.
 Elements.ElementsTreeElement.EditTagBlacklist = new Set(['html', 'head', 'body']);