Fix closure compile.

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="../uber/uber_utils.js">
 <include src="extension_code.js">
 <include src="extension_commands_overlay.js">
 <include src="extension_error_overlay.js">
 <include src="extension_focus_manager.js">
 <include src="extension_list.js">
@@ skipping 362 matching lines @@
 
   /**
    * Sets the given overlay to show. This hides whatever overlay is currently
    * showing, if any.
    * @param {HTMLElement} node The overlay page to show. If null, all overlays
    *     are hidden.
    */
   ExtensionSettings.showOverlay = function(node) {
     var pageDiv = $('extension-settings');
     pageDiv.style.width = node ? window.getComputedStyle(pageDiv).width : '';
-    document.body.classList.toggle('no-scroll', node);
+    document.body.classList.toggle('no-scroll', !!node);
 
     var currentlyShowingOverlay = ExtensionSettings.getCurrentOverlay();
     if (currentlyShowingOverlay) {
       currentlyShowingOverlay.classList.remove('showing');
       cr.dispatchSimpleEvent($('overlay'), 'cancelOverlay');
     }
 
     if (node) {
       var lastFocused = document.activeElement;
       $('overlay').addEventListener('cancelOverlay', function f() {
@@ skipping 65 matching lines @@
 
   // Export
   return {
     ExtensionSettings: ExtensionSettings
   };
 });
 
 window.addEventListener('load', function(e) {
   extensions.ExtensionSettings.getInstance().initialize();
 });