Add Settings bluetooth page test

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 2b8e53d2afbd2ca0e7258940699d20d58446fe5a..d686dae0929745900b93e29f7c9770d2f22e37e3 100644
--- a/chrome/test/data/webui/settings/settings_page_browsertest.js
+++ b/chrome/test/data/webui/settings/settings_page_browsertest.js
@@ -36,9 +36,9 @@ SettingsPageBrowserTest.prototype = {
   getPage: function(type) {
     var settings = document.querySelector('cr-settings');
     assertTrue(!!settings);
-    var settingsUi = settings.shadowRoot.querySelector('settings-ui');
+    var settingsUi = settings.$$('settings-ui');
     assertTrue(!!settingsUi);
-    var settingsMain = settingsUi.shadowRoot.querySelector('settings-main');
+    var settingsMain = settingsUi.$$('settings-main');
     assertTrue(!!settingsMain);
     var pages = settingsMain.$.pageContainer;
     assertTrue(!!pages);