Added menuItem icon support, and little API for menu modification.

chrome/browser/resources/shared/js/cr/ui/menu.js

 // Copyright (c) 2012 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.
 
 cr.define('cr.ui', function() {
 
   /** @const */ var MenuItem = cr.ui.MenuItem;
 
   /**
    * Creates a new menu element.
@@ skipping 16 matching lines @@
       this.addEventListener('mouseout', this.handleMouseOut_);
 
       // Decorate the children as menu items.
       var children = this.children;
       for (var i = 0, child; child = children[i]; i++) {
         cr.ui.decorate(child, MenuItem);
       }
     },
 
     /**
+     * Adds menu item at the end of the list.
+     * @param {Object} item Menu item properties.
+     * @return {cr.ui.MenuItem} The created menu item.
+     */
+    addMenuItem: function(item) {
+      var menuItem = this.ownerDocument.createElement('menuitem');
+      this.appendChild(menuItem);
+
+      cr.ui.decorate(menuItem, MenuItem);
+
+      if (item.label)
+        menuItem.label = item.label;
+
+      if (item.iconUrl)
+        menuItem.iconUrl = item.iconUrl;
+
+      return menuItem;
+    },
+
+    /**
+     * Adds separator at the end of the list.
+     */
+    addSeparator: function() {
+      var separator = this.ownerDocument.createElement('hr');
+      this.appendChild(separator);
+    },
+
+    /**
+     * Clears menu.
+     */
+    clear: function() {
+      this.textContent = '';
+    },
+
+    /**
      * Walks up the ancestors of |el| until a menu item belonging to this menu
      * is found.
      * @param {Element} el The element to start searching from.
      * @return {cr.ui.MenuItem} The found menu item or null.
      * @private
      */
     findMenuItem_: function(el) {
       while (el && el.parentNode != this) {
         el = el.parentNode;
       }
@@ skipping 25 matching lines @@
      */
     get selectedItem() {
       return this.children[this.selectedIndex];
     },
     set selectedItem(item) {
       var index = Array.prototype.indexOf.call(this.children, item);
       this.selectedIndex = index;
     },
 
     /**
+     * Menu length
+     */
+    get length() {
+      return this.children.length;
+    },
+
+    /**
      * This is the function that handles keyboard navigation. This is usually
      * called by the element responsible for managing the menu.
      * @param {Event} e The keydown event object.
      * @return {boolean} Whether the event was handled be the menu.
      */
     handleKeyDown: function(e) {
       var item = this.selectedItem;
 
       var self = this;
       function selectNextVisible(m) {
@@ skipping 49 matching lines @@
    * @type {number}
    */
   cr.defineProperty(Menu, 'selectedIndex', cr.PropertyKind.JS,
       selectedIndexChanged);
 
   // Export
   return {
     Menu: Menu
   };
 });