Support first letter navigation in Panel.

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');
 
@@ skipping 18 matching lines @@
   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);
 };
+
+PanelMenuItem.prototype = {
+  get text() {
+    return this.element.textContent;
+  }
+};