Add Mocha based tests for Settings pages

chrome/test/data/webui/settings/settings_page_browsertest.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 Prototype for Settings page tests. */
+
+/** @const {string} Path to root from chrome/test/data/webui/settings/. */
+var ROOT_PATH = '../../../../../';
+
+// Polymer BrowserTest fixture.
+GEN_INCLUDE(
+    [ROOT_PATH + 'chrome/test/data/webui/polymer_browser_test_base.js']);
+
+/**
+ * @constructor
+ * @extends {PolymerTest}
+*/
+function SettingsPageBrowserTest() {}
+
+SettingsPageBrowserTest.prototype = {
+  __proto__: PolymerTest.prototype,
+
+  /** @override */
+  browsePreload: 'chrome://md-settings/',
+
+  /** @override */
+  extraLibraries: PolymerTest.getLibraries(ROOT_PATH),
+
+  /** @override */
+  runAccessibilityChecks: false,
+
+  /**
+   * @param {string} type The settings page type, e.g. 'advanced' or 'basic'.
+   * @return {Node} The DOM node for the page.
+   */
+  getPage: function(type) {
+    var settings = document.querySelector('cr-settings');
+    assertTrue(!!settings);
+    var settingsUi = settings.shadowRoot.querySelector('settings-ui');
+    assertTrue(!!settingsUi);
+    var settingsMain = settingsUi.shadowRoot.querySelector('settings-main');
+    assertTrue(!!settingsMain);
+    var pages = settingsMain.$.pageContainer;
+    assertTrue(!!pages);
+    var pageType = 'settings-' + type + '-page';
+    var page = pages.querySelector(pageType);
+    assertTrue(!!page);
+    return page;
+  },
+
+  /**
+   * @param {Node} page The DOM node for the settings page containing |section|.
+   * @param {string} section The settings page section, e.g. 'appearance'.
+   * @return {Node} The DOM node for the section.
+   */
+  getSection: function(page, section) {
+    var sections = page.shadowRoot.querySelectorAll('settings-section');
+    assertTrue(!!sections);
+    var len = sections.length;
+    assertGT(len, 0);
+    for (var i = 0; i < len; ++i) {
+      var s = sections[i];
+      if (s.section == section)
+        return s;
+    }
+    assertNotReached('Section not found: ' + section + ' in ' + page);
+    return undefined;
+  },
+};