[MD settings] advanced toggle; add scrollWhenReady

chrome/browser/resources/settings/basic_page/basic_page.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-basic-page' is the settings page containing the basic settings.
  */
 Polymer({
   is: 'settings-basic-page',
@@ skipping 31 matching lines @@
 
   },
 
   /**
    * @type {string} Selector to get the sections.
    * TODO(michaelpg): replace duplicate docs with @override once b/24294625
    * is fixed.
    */
   sectionSelector: 'settings-section',
 
-  /** @override */
-  attached: function() {
-    /** @override */
-    this.scroller = this.parentElement;
-  },
-
   onResetDone_: function() {
     this.showResetProfileBanner_ = false;
   },
 });