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

chrome/test/data/webui/settings/startup_urls_page_test.js

 // Copyright 2016 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.
 
 cr.define('settings_startup_urls_page', function() {
   /**
    * @constructor
    * @implements {settings.StartupUrlsPageBrowserProxy}
    * @extends {settings.TestBrowserProxy}
    */
@@ skipping 211 matching lines @@
       Polymer.dom.flush();
       assertTrue(!!page.$$('settings-startup-url-dialog'));
     });
 
     test('EditPage_OpensDialog', function() {
       assertFalse(!!page.$$('settings-startup-url-dialog'));
       page.fire(settings.EDIT_STARTUP_URL_EVENT, createSampleUrlEntry());
       Polymer.dom.flush();
       assertTrue(!!page.$$('settings-startup-url-dialog'));
     });
+
+    test('StartupPagesChanges_CloseOpenEditDialog', function() {
+      var entry1 = {
+        modelIndex: 2,
+        title: 'Test page 1',
+        tooltip: 'test tooltip',
+        url: 'chrome://bar',
+      };
+
+      var entry2 = {
+        modelIndex: 2,
+        title: 'Test page 2',
+        tooltip: 'test tooltip',
+        url: 'chrome://foo',
+      };
+
+      cr.webUIListenerCallback('update-startup-pages', [entry1, entry2]);
+      page.fire(settings.EDIT_STARTUP_URL_EVENT, entry2);
+      Polymer.dom.flush();
+
+      assertTrue(!!page.$$('settings-startup-url-dialog'));
+      cr.webUIListenerCallback('update-startup-pages', [entry1]);
+      Polymer.dom.flush();
+
+      assertFalse(!!page.$$('settings-startup-url-dialog'));
+    });
   });
 
   /** @return {!StartupPageInfo} */
   function createSampleUrlEntry() {
     return {
       modelIndex: 2,
       title: 'Test page',
       tooltip: 'test tooltip',
       url: 'chrome://foo',
     };
@@ skipping 25 matching lines @@
     test('MenuOptions_Remove', function() {
       var removeButton = element.shadowRoot.querySelector('#remove')
       MockInteractions.tap(removeButton);
       return browserProxy.whenCalled('removeStartupPage').then(
           function(modelIndex) {
             assertEquals(element.model.modelIndex, modelIndex);
           });
     });
   });
 });