Initial accounts options page.

chrome/browser/resources/options/options_page.js

 // Copyright (c) 2010 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.
 
 ///////////////////////////////////////////////////////////////////////////////
 // OptionsPage class:
 
 /**
  * Base class for options page.
  * @constructor
  * @param {string} name Options page name, also defines id of the div element
  *     containing the options view and the name of options page navigation bar
  *     item as name+'PageNav'.
  * @param {string} title Options page title, used for navigation bar
+ * @extends {EventTarget}
  */
 function OptionsPage(name, title, pageDivName) {
   this.name = name;
   this.title = title;
   this.pageDivName = pageDivName;
   this.pageDiv = $(this.pageDivName);
   this.tab = null;
 }
 
 OptionsPage.registeredPages_ = {};
@@ skipping 89 matching lines @@
 
 /**
  * Initializes the complete options page.  This will cause
  * all C++ handlers to be invoked to do final setup.
  */
 OptionsPage.initialize = function() {
   chrome.send('coreOptionsInitialize');
 };
 
 OptionsPage.prototype = {
+  __proto__: cr.EventTarget.prototype,
+
   /**
    * Initializes page content.
    */
   initializePage: function() {},
 
   /**
    * Gets page visibility state.
    */
   get visible() {
     var page = $(this.pageDivName);
     return page.ownerDocument.defaultView.getComputedStyle(
         page).display == 'block';
   },
 
   /**
    * Sets page visibility.
    */
   set visible(visible) {
     if ((this.visible && visible) || (!this.visible && !visible))
       return;
 
     if (visible) {
       window.history.pushState({pageName: this.name},
                                this.title,
                                '/' + this.name);
       this.pageDiv.style.display = 'block';
       if (this.isOverlay) {
         var overlay = $('overlay');
         overlay.classList.remove('hidden');
-        overlay.classList.add('overlay-visible');
       }
       if (this.tab) {
         this.tab.classList.add('navbar-item-selected');
         if (this.tab.parentNode && this.tab.parentNode.id == 'subpagesnav')
           this.tab.classList.remove('hidden');
       }
     } else {
       if (this.isOverlay) {
         var overlay = $('overlay');
         overlay.classList.add('hidden');
-        overlay.classList.remove('overlay-visible');
       }
       this.pageDiv.style.display = 'none';
       if (this.tab) {
         this.tab.classList.remove('navbar-item-selected');
         if (this.tab.parentNode && this.tab.parentNode.id == 'subpagesnav')
           this.tab.classList.add('hidden');
       }
     }
+
+    cr.dispatchPropertyChange(this, 'visible', visible, !visible);
   }
 };