Fixing accessibility bug with extensions preferences

chrome/browser/resources/extensions/extensions.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.
 
 // <include src="../../../../ui/webui/resources/js/cr/ui/focus_row.js">
 // <include src="../../../../ui/webui/resources/js/cr/ui/focus_grid.js">
 // <include src="../uber/uber_utils.js">
 // <include src="drag_and_drop_handler.js">
 // <include src="extension_code.js">
 // <include src="extension_commands_overlay.js">
@@ skipping 374 matching lines @@
           lastFocused.focus();
 
         $('overlay').removeEventListener('cancelOverlay', f);
         uber.replaceState({}, '');
       });
       node.classList.add('showing');
     }
 
     var pages = document.querySelectorAll('.page');
     for (var i = 0; i < pages.length; i++) {
-      pages[i].setAttribute('aria-hidden', node ? 'true' : 'false');
+      var hidden = (node != pages[i]) ? 'true' : 'false';
+      pages[i].setAttribute('aria-hidden', hidden);
     }
 
     $('overlay').hidden = !node;
 
     if (node)
       ExtensionSettings.focusOverlay();
 
     // If drag-drop for external Extension installation is available, enable
     // drag-drop when there is any overlay showing other than the usual overlay
     // shown when drag-drop is started.
@@ skipping 55 matching lines @@
 
   // Export
   return {
     ExtensionSettings: ExtensionSettings
   };
 });
 
 window.addEventListener('load', function(e) {
   extensions.ExtensionSettings.getInstance().initialize();
 });