[MD settings] update site details permission layout

chrome/test/data/webui/settings/site_details_permission_tests.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 Suite of tests for site-details. */
 cr.define('site_details_permission', function() {
   function registerTests() {
     suite('SiteDetailsPermission', function() {
       /**
        * A site list element created before each test.
@@ skipping 75 matching lines @@
         testElement.category = settings.ContentSettingsTypes.CAMERA;
         testElement.site = {
           origin: origin,
           embeddingOrigin: '',
         };
 
         return browserProxy.whenCalled('getExceptionList').then(function() {
           assertFalse(testElement.$.details.hidden);
 
           var header = testElement.$.details.querySelector(
-              '.permission-header');
+              '#permissionHeader');
           assertEquals('Camera', header.innerText.trim(),
               'Widget should be labelled correctly');
 
           // Flip the permission and validate that prefs stay in sync.
           return validatePermissionFlipWorks(origin, true);
         }).then(function() {
           browserProxy.resetResolver('setCategoryPermissionForOrigin');
           return validatePermissionFlipWorks(origin, false);
         }).then(function() {
           browserProxy.resetResolver('setCategoryPermissionForOrigin');
@@ skipping 18 matching lines @@
         }).then(function() {
           assertTrue(testElement.$.details.hidden);
         });
       });
     });
   }
   return {
     registerTests: registerTests,
   };
 });