Options: Notify overlays that they will be closed if the options tab is closed.

chrome/browser/resources/options/options.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.
 
 var AddLanguageOverlay = options.AddLanguageOverlay;
 var AdvancedOptions = options.AdvancedOptions;
 var AlertOverlay = options.AlertOverlay;
 var AutofillEditAddressOverlay = options.AutofillEditAddressOverlay;
 var AutofillEditCreditCardOverlay = options.AutofillEditCreditCardOverlay;
 var AutofillOptions = options.AutofillOptions;
@@ skipping 193 matching lines @@
   $('settings-title').onclick = function() {
     OptionsPage.navigateToPage(BrowserOptions.getInstance().name);
   };
 }
 
 document.addEventListener('DOMContentLoaded', load);
 
 window.onpopstate = function(e) {
   options.OptionsPage.setState(e.state);
 };
+
+window.onbeforeunload = function() {
+  options.OptionsPage.willClose();
+};