[MD settings] idle load basic and advanced pages

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

Index: chrome/test/data/webui/settings/settings_page_browsertest.js
diff --git a/chrome/test/data/webui/settings/settings_page_browsertest.js b/chrome/test/data/webui/settings/settings_page_browsertest.js
index a1c5ef5426d0656bc5cccf3cf418020abd98521f..56e7d6f82ad75de9e5a91c8767e3bca402939741 100644
--- a/chrome/test/data/webui/settings/settings_page_browsertest.js
+++ b/chrome/test/data/webui/settings/settings_page_browsertest.js
@@ -62,6 +62,11 @@ SettingsPageBrowserTest.prototype = {
     var pageType = 'settings-' + type + '-page';
     var page = settingsMain.$$(pageType);
     assertTrue(!!page);
+    var idleRender = page.$$('[is=settings-idle-render]')

[dpapad, 2017/01/31 23:10:13]

Can we be more specific in the selector, as follows? 
page.$$('template[is=settings-idle-render])

This makes it more obvious that a settings-idle-render attribute is only
expected in a <template> tag.

[dschuyler, 2017/01/31 23:53:03]

Done.

+    if (idleRender) {
+      idleRender.get();
+      Polymer.dom.flush();
+    }
     return page;
   },