Avoid changing select element via synthesized keydown from ChromeVox test

chrome/browser/resources/chromeos/chromevox/testing/chromevox_e2e_test_base.js

 // Copyright 2014 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.
 
 GEN_INCLUDE([
     'common.js',
     'callback_helper.js']);
 
 /**
  * Base test fixture for ChromeVox end to end tests.
@@ skipping 71 matching lines @@
       active: true,
       url: url
     };
     chrome.tabs.create(createParams, function(tab) {
       if (opt_callback)
         opt_callback(tab.url);
     });
   },
 
   /**
-   * Send a key to the page.
+   * Increment the selected index of a select control.
    * @param {number} tabId Of the page.
-   * @param {string} key Name of the key (e.g. ArrowDown).
    * @param {string} elementQueryString
    */
-  sendKeyToElement: function(tabId, key, elementQueryString) {
+  incrementSelectedIndex: function(tabId, elementQueryString) {
     var code = TestUtils.extractHtmlFromCommentEncodedString(function() {/*!
-      var target = document.body.querySelector('$1');
+      var target = document.body.querySelector('$0');
       target.focus();
-      var evt = new KeyboardEvent('keydown', {key: '$0'});
-      document.activeElement.dispatchEvent(evt);
-    */}, [key, elementQueryString]);
+      target.selectedIndex++;
+    */}, [elementQueryString]);
 
     chrome.tabs.executeScript(tabId, {code: code});
   },
 
   /**
    * Creates a callback that optionally calls {@code opt_callback} when
    * called.  If this method is called one or more times, then
    * {@code testDone()} will be called when all callbacks have been called.
    * @param {Function=} opt_callback Wrapped callback that will have its this
    *        reference bound to the test fixture.
    * @return {Function}
    */
   newCallback: function(opt_callback) {
     return this.callbackHelper_.wrap(opt_callback);
   }
 };