MD Settings: Close edit startup URL dialog, if underlying URL list changes.

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 15 matching lines @@
     showStartupUrlDialog_: Boolean,
 
     /** @private {?StartupPageInfo} */
     startupUrlDialogModel_: Object,
   },
 
   /** @override */
   attached: function() {
     this.browserProxy_ = settings.StartupUrlsPageBrowserProxyImpl.getInstance();
     this.addWebUIListener('update-startup-pages', function(startupPages) {
+      // If an "edit" URL dialog was open, close it, because the underlying page
+      // might have just been removed (and model indices have changed anyway).
+      if (this.startupUrlDialogModel_)
+        this.destroyUrlDialog_();
       this.startupPages_ = startupPages;
       this.updateScrollableContents();
     }.bind(this));
     this.browserProxy_.loadStartupPages();
 
     this.addEventListener(settings.EDIT_STARTUP_URL_EVENT, function(event) {
       this.startupUrlDialogModel_ = event.detail;
-      this.openDialog_();
+      this.showStartupUrlDialog_ = true;
       event.stopPropagation();
     }.bind(this));
   },
 
   /** @private */
   onAddPageTap_: function() {
-    this.openDialog_();
-  },
-
-  /**
-   * 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('close', function() {
-        this.showStartupUrlDialog_ = false;
-        this.startupUrlDialogModel_ = null;
-      }.bind(this));
-    }.bind(this));
   },
 
   /** @private */
+  destroyUrlDialog_: function() {
+    this.showStartupUrlDialog_ = false;
+    this.startupUrlDialogModel_ = null;
+  },
+
+  /** @private */
   onUseCurrentPagesTap_: function() {
     this.browserProxy_.useCurrentPages();
   },
 });