a11y/options: Fix initial tab focus bug on supervised user history page.

chrome/test/data/webui/history_browsertest.js

 // Copyright (c) 2012 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 "chrome/test/data/webui/history_ui_browsertest.h"');
 
 /** @const */ var TOTAL_RESULT_COUNT = 160;
 /** @const */ var WAIT_TIMEOUT = 200;
 
 /**
@@ skipping 759 matching lines @@
  * history database and displayed in the UI.
  */
 TEST_F('HistoryWebUIRealBackendTest', 'basic', function() {
   // Check that there are two days of entries, and three entries in total.
   assertEquals(2, document.querySelectorAll('.day').length);
   assertEquals(3, document.querySelectorAll('.entry').length);
 
   testDone();
 });
 
+TEST_F('HistoryWebUIRealBackendTest', 'atLeastOneFocusable', function() {
+  assertEquals(1, document.querySelectorAll('[tabindex="0"]').length);
+  testDone();
+});
+
 /**
  * Test individual deletion of history entries.
  */
 TEST_F('HistoryWebUIRealBackendTest', 'singleDeletion', function() {
   // Deletes the history entry represented by |entryElement|, and calls callback
   // when the deletion is complete.
   var removeEntry = function(entryElement, callback) {
     var dropDownButton = entryElement.querySelector('.drop-down');
     var removeMenuItem = $('remove-visit');
 
@@ skipping 65 matching lines @@
   expectTrue(removeVisit.disabled);
 
   // Attempting to remove items anyway should fail.
   historyModel.removeVisitsFromHistory(historyModel.visits_, function () {
     // The callback is only called on success.
     testDone([false, 'Delete succeeded even though it was prohibited.']);
   });
   waitForCallback('deleteFailed', testDone);
 });
 
+TEST_F('HistoryWebUIDeleteProhibitedTest', 'atLeastOneFocusable', function() {
+  assertEquals(1, document.querySelectorAll('[tabindex="0"]').length);
+  testDone();
+});
+
 /**
  * Fixture for History WebUI testing IDN.
  * @extends {BaseHistoryWebUITest}
  * @constructor
  */
 function HistoryWebUIIDNTest() {}
 
 HistoryWebUIIDNTest.prototype = {
   __proto__: BaseHistoryWebUITest.prototype,
 
@@ skipping 51 matching lines @@
 TEST_F('HistoryWebUIWithSchemesTest', 'groupingWithSchemes', function() {
   // Switch to the week view.
   $('timeframe-filter-week').click();
   waitForCallback('historyResult', function() {
     // Each URL should be organized under a different "domain".
     expectEquals(document.querySelectorAll('.entry').length, 4);
     expectEquals(document.querySelectorAll('.site-domain-wrapper').length, 4);
     testDone();
   });
 });