Page zoom improvements

chrome/browser/ui/webui/options/advanced_options_browsertest.js

 // Copyright (c) 2011 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.
 
 /**
  * TestFixture for advanced options WebUI testing.
  * @extends {testing.Test}
  * @constructor
  **/
 function AdvancedOptionsWebUITest() {}
 
 AdvancedOptionsWebUITest.prototype = {
   __proto__: testing.Test.prototype,
 
   /**
    * Browse to advanced options.
    **/
   browsePreload: 'chrome://settings/advanced',
+
+  /**
+   * Register a mock handler.
+   * @type {Function}
+   * @override
+   */
+  preLoad: function() {
+    this.makeAndRegisterMockHandler(['defaultZoomFactorAction']);
+  },
 };
 
-// Test opening the advanced options has correct location.
+/**
+ * The expected minimum length of the |defaultZoomFactor| element.
+ * @type {number}
+ * @const
+ */
+var defaultZoomFactorMinimumLength = 10;
+
+/**
+ * Test opening the advanced options has correct location.
+ */
 TEST_F('AdvancedOptionsWebUITest', 'testOpenAdvancedOptions', function() {
   assertEquals(this.browsePreload, document.location.href);
 });
+
+/**
+ * Test the default zoom factor select element.
+ */
+TEST_F('AdvancedOptionsWebUITest', 'testDefaultZoomFactor', function() {
+  // Verify that the zoom factor element exists.
+  var defaultZoomFactor = $('defaultZoomFactor');
+  assertNotEquals(defaultZoomFactor, null);
+
+  // Verify that the zoom factor element has a reasonable number of choices.
+  expectGE(defaultZoomFactor.options.length, defaultZoomFactorMinimumLength);
+
+  // Simulate a change event, selecting the highest zoom value.  Verify that
+  // the javascript handler was invoked once.
+  this.mockHandler.expects(once()).defaultZoomFactorAction(NOT_NULL).
+      will(callFunction(function() { }));
+  defaultZoomFactor.selectedIndex = defaultZoomFactor.options.length - 1;
+  var event = { target: defaultZoomFactor };
+  if (defaultZoomFactor.onchange) defaultZoomFactor.onchange(event);
+});
+