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

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

Index: chrome/test/data/webui/settings/advanced_page_browsertest.js
diff --git a/chrome/test/data/webui/settings/advanced_page_browsertest.js b/chrome/test/data/webui/settings/advanced_page_browsertest.js
index 39b85442f8bbde95a9c9cd7982c5bb5897e60618..5f14ab4bd7217e36bd1059235818adb1d93042c4 100644
--- a/chrome/test/data/webui/settings/advanced_page_browsertest.js
+++ b/chrome/test/data/webui/settings/advanced_page_browsertest.js
@@ -41,7 +41,7 @@ TEST_F('SettingsAdvancedPageBrowserTest', 'MAYBE_Load', function() {
     });
 
     test('advanced pages', function() {
-      var page = self.getPage('basic');
+      var page = self.page;
       var sections = ['privacy', 'passwordsAndForms', 'languages', 'downloads',
           'reset'];
       if (cr.isChromeOS)
@@ -49,7 +49,7 @@ TEST_F('SettingsAdvancedPageBrowserTest', 'MAYBE_Load', function() {
 
       for (var i = 0; i < sections.length; i++) {
         var section = self.getSection(page, sections[i]);
-        expectTrue(!!section);
+        assertTrue(!!section);

[dpapad, 2017/03/16 20:47:16]

FYI, changed this because the expect() made no sense here. The test can't
actually continue if it fails (there is a null dereference in the first line of
verifySubpagesHidden).

         self.verifySubpagesHidden(section);
       }
     });