Implement ChromeVox Next menus.

chrome/browser/resources/chromeos/chromevox/cvox2/background/panel_menu_item.js

+// 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.
+
+/**
+ * @fileoverview An item in a drop-down menu in the ChromeVox panel.
+ */
+
+goog.provide('PanelMenuItem');
+
+/**
+ * @param {string} menuItemTitle The title of the menu item.
+ * @param {string} menuItemShortcut The keystrokes to select this item.
+ * @param {Function} callback The function to call if this item is selected.
+ * @constructor
+ */
+PanelMenuItem = function(menuItemTitle, menuItemShortcut, callback) {
+  this.callback = callback;

[David Tseng, 2016/01/12 20:10:57]

js doc

+
+  this.element = document.createElement('tr');
+  this.element.className = 'menu-item';
+  this.element.tabIndex = -1;
+  this.element.setAttribute('role', 'menuitem');
+
+  this.element.addEventListener('mouseover', (function(evt) {
+    this.element.focus();
+  }).bind(this), false);
+
+  var title = document.createElement('td');
+  title.className = 'menu-item-title';
+  title.textContent = menuItemTitle;
+  this.element.appendChild(title);
+
+  var shortcut = document.createElement('td');
+  shortcut.className = 'menu-item-shortcut';
+  shortcut.textContent = menuItemShortcut;
+  this.element.appendChild(shortcut);
+};