Don't rely on the second argument to DOMTokenList.toggle in about:policy.

chrome/browser/resources/policy.js

 // Copyright (c) 2013 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('policy', function() {
   /**
    * A box that shows the status of cloud policy for a device or user.
    * @constructor
    * @extends {HTMLFieldSetElement}
    */
@@ skipping 144 matching lines @@
       // overflow the column once it has been hidden and replaced by a link.
       var valueContainer = this.querySelector('.value-container');
       if (valueContainer.valueWidth == undefined) {
         valueContainer.valueWidth =
             valueContainer.querySelector('.value').offsetWidth;
       }
 
       // Determine whether the contents of the value column overflows. The
       // visibility of the contents, replacement link and additional row
       // containing the complete value that depend on this are handled by CSS.
-      this.classList.toggle(
-          'has-overflowed-value',
-          valueContainer.offsetWidth < valueContainer.valueWidth);
+      if (valueContainer.offsetWidth < valueContainer.valueWidth)
+        this.classList.add('has-overflowed-value');
+      else
+        this.classList.remove('has-overflowed-value');
     },
 
     /**
      * Update the text of the link that toggles the visibility of an additional
      * row containing the complete policy value, depending on the toggle state.
      * @private
      */
     updateToggleExpandedValueText_: function(event) {
       this.querySelector('.toggle-expanded-value').textContent =
           loadTimeData.getString(
@@ skipping 94 matching lines @@
      */
     filter: function() {
       var showUnset = $('show-unset').checked;
       var policies = this.getElementsByTagName('tbody');
       for (var i = 0; i < policies.length; i++) {
         var policy = policies[i];
         policy.hidden =
             policy.unset && !showUnset ||
             policy.name.toLowerCase().indexOf(this.filterPattern_) == -1;
       }
-      this.parentElement.classList.toggle(
-          'empty', !this.querySelector('tbody:not([hidden])'));
+      if (this.querySelector('tbody:not([hidden])'))
+        this.parentElement.classList.remove('empty');
+      else
+        this.parentElement.classList.add('empty');
       setTimeout(this.checkOverflow_.bind(this), 0);
     },
 
     /**
      * Check the table columns for overflow.
      * @private
      */
     checkOverflow_: function() {
       var policies = this.getElementsByTagName('tbody');
       for (var i = 0; i < policies.length; i++) {
@@ skipping 242 matching lines @@
   return {
     Page: Page
   };
 });
 
 // Have the main initialization function be called when the page finishes
 // loading.
 document.addEventListener(
     'DOMContentLoaded',
     policy.Page.getInstance().initialize.bind(policy.Page.getInstance()));