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

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

Index: chrome/test/data/webui/settings/startup_urls_page_test.js
diff --git a/chrome/test/data/webui/settings/startup_urls_page_test.js b/chrome/test/data/webui/settings/startup_urls_page_test.js
index a2dbdc8d6345f94a7d7a71ce5832f0c96dc93d8a..d212a209ddf52a401730ea0cbdd4d558bfd43db1 100644
--- a/chrome/test/data/webui/settings/startup_urls_page_test.js
+++ b/chrome/test/data/webui/settings/startup_urls_page_test.js
@@ -229,6 +229,32 @@ cr.define('settings_startup_urls_page', function() {
       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} */