Migrate <cr-dialog> from PaperDialogBehavior to native <dialog>.

chrome/browser/resources/settings/on_startup_page/startup_urls_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-startup-urls-page' is the settings page
  * containing the urls that will be opened when chrome is started.
  */
 
 Polymer({
@@ skipping 41 matching lines @@
   /**
    * Opens the dialog and registers a listener for removing the dialog from the
    * DOM once is closed. The listener is destroyed when the dialog is removed
    * (because of 'restamp').
    * @private
    */
   openDialog_: function() {
     this.showStartupUrlDialog_ = true;
     this.async(function() {
       var dialog = this.$$('settings-startup-url-dialog');
-      dialog.addEventListener('iron-overlay-closed', function() {
+      dialog.addEventListener('close', function() {
         this.showStartupUrlDialog_ = false;
         this.startupUrlDialogModel_ = null;
       }.bind(this));
     }.bind(this));
   },
 
   /** @private */
   onUseCurrentPagesTap_: function() {
     this.browserProxy_.useCurrentPages();
   },
 });