MD Settings: rework how advanced UI shows

chrome/browser/resources/settings/settings_menu/settings_menu.js

 // Copyright 2015 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
  * 'settings-menu' shows a menu with a hardcoded set of pages and subpages.
  */
 Polymer({
   is: 'settings-menu',
 
   behaviors: [settings.RouteObserverBehavior],
 
   properties: {
+    advancedOpened: {
+      type: Boolean,
+      notify: true,
+    },
+
     /** @private */
     aboutSelected_: Boolean,
 
     /**
      * Dictionary defining page visibility.
      * @type {!GuestModePageVisibility}
      */
     pageVisibility: {
       type: Object,
     },
   },
 
-  attached: function() {

[dpapad, 2016/10/17 19:11:43]

Nice!!

[Dan Beam, 2016/10/17 20:52:17]

Acknowledged.

-    document.addEventListener('toggle-advanced-page', function(e) {
-      if (e.detail)
-        this.$.advancedPage.open();
-      else
-        this.$.advancedPage.close();
-    }.bind(this));
-
-    this.$.advancedPage.addEventListener('paper-submenu-open', function() {
-      this.fire('toggle-advanced-page', true);
-    }.bind(this));
-
-    this.$.advancedPage.addEventListener('paper-submenu-close', function() {
-      this.fire('toggle-advanced-page', false);
-    }.bind(this));
-
-    this.fire('toggle-advanced-page',
-              settings.Route.ADVANCED.contains(settings.getCurrentRoute()));
-  },
-
   /**
    * @param {!settings.Route} newRoute
    */
   currentRouteChanged: function(newRoute) {
     // Make the three menus mutually exclusive.
     if (settings.Route.ABOUT.contains(newRoute)) {
       this.aboutSelected_ = true;
       this.$.advancedMenu.selected = null;
       this.$.basicMenu.selected = null;
     } else if (settings.Route.ADVANCED.contains(newRoute)) {
@@ skipping 21 matching lines @@
 
   /**
    * @param {boolean} opened Whether the menu is expanded.
    * @return {string} Which icon to use.
    * @private
    * */
   arrowState_: function(opened) {
     return opened ? 'settings:arrow-drop-up' : 'cr:arrow-drop-down';
   },
 });