Options: Remove the hidden class, since we override the hidden attribute to set

chrome/browser/resources/options/content_settings.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.
 
 cr.define('options', function() {
 
   var OptionsPage = options.OptionsPage;
 
   //////////////////////////////////////////////////////////////////////////////
   // ContentSettings class:
@@ skipping 81 matching lines @@
                                ' list[mode=normal]');
 
     exceptionsList.setExceptions(list);
   };
 
   ContentSettings.setOTRExceptions = function(type, list) {
     var exceptionsList =
         document.querySelector('div[contentType=' + type + ']' +
                                ' list[mode=otr]');
 
-    exceptionsList.parentNode.classList.remove('hidden');
+    exceptionsList.parentNode.hidden = false;
     exceptionsList.setExceptions(list);
   };
 
   /**
    * Sets the initial value for the Third Party Cookies checkbox.
    * @param {boolean=} block True if we are blocking third party cookies.
    */
   ContentSettings.setBlockThirdPartyCookies = function(block) {
     $('block-third-party-cookies').checked = block;
   };
@@ skipping 14 matching lines @@
                                'list[mode=' + mode + ']');
     exceptionsList.patternValidityCheckComplete(pattern, valid);
   };
 
   // Export
   return {
     ContentSettings: ContentSettings
   };
 
 });