Added Home, end, PageUp, PageDown support in the ChromeVox menu

chrome/browser/resources/chromeos/chromevox/cvox2/background/panel_menu.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 A drop-down menu in the ChromeVox panel.
  */
 
 goog.provide('PanelMenu');
 goog.provide('PanelNodeMenu');
@@ skipping 151 matching lines @@
       if (delta >= 0)
         this.activeIndex_ = 0;
       else
         this.activeIndex_ = this.menus_.length - 1;
     }
 
     this.items_[this.activeIndex_].element.focus();
   },
 
   /**
+   * Sets the active menu item index to be 0.
+   */
+  scrollToTop: function() {
+    this.activeIndex_ = 0;
+    this.items_[this.activeIndex_].element.focus();
+  },
+
+  /**
+   * Sets the active menu item index to be the last index.
+   */
+  scrollToBottom: function() {
+    this.activeIndex_ = this.items_.length - 1;
+    this.items_[this.activeIndex_].element.focus();
+  },
+
+  /**
    * Get the callback for the active menu item.
    * @return {Function} The callback.
    */
   getCallbackForCurrentItem: function() {
     if (this.activeIndex_ >= 0 && this.activeIndex_ < this.items_.length) {
       return this.items_[this.activeIndex_].callback;
     }
     return null;
   },
 
@@ skipping 67 matching lines @@
 PanelNodeMenu.prototype = {
   __proto__: PanelMenu.prototype,
 
   /** @override */
   activate: function() {
     var activeItem = this.activeIndex_;
     PanelMenu.prototype.activate.call(this);
     this.activateItem(activeItem);
   }
 };