MD Settings: Lazy load the contents of the "advanced" settings.

chrome/test/data/webui/settings/passwords_and_forms_browsertest.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.
 
 /** @fileoverview Runs the Polymer Passwords and Forms tests. */
 
 /** @const {string} Path to root from chrome/test/data/webui/settings/. */
 var ROOT_PATH = '../../../../../';
 
 // Polymer BrowserTest fixture.
@@ skipping 14 matching lines @@
   __proto__: PolymerTest.prototype,
 
   /** @override */
   browsePreload: 'chrome://md-settings/passwords_and_forms_page/' +
     'passwords_and_forms_page.html',
 
   /** @override */
   extraLibraries: PolymerTest.getLibraries(ROOT_PATH).concat([
       '../fake_chrome_event.js',
       'fake_settings_private.js',
+      'ensure_lazy_loaded.js',
   ]),
 
   /** @override */
   setUp: function() {
     PolymerTest.prototype.setUp.call(this);
 
     // Test is run on an individual element that won't have a page language.
     this.accessibilityAuditConfig.auditRulesToIgnore.push('humanLangMissing');
+
+    settings.ensureLazyLoaded();
   },
 };
 
 /** This test will validate that the section is loaded with data. */
 TEST_F('PasswordsAndFormsBrowserTest', 'uiTests', function() {
   var passwordManager;
   var autofillManager;
 
   /**
    * Creates a new passwords and forms element.
@@ skipping 222 matching lines @@
         Polymer.dom.flush();
 
         assertTrue(!!element.$$('#passwordsExtensionIndicator'));
         destroyPrefs(prefs);
       });
     });
   });
 
   mocha.run();
 });