Disable "Choose file" button if "Favorites" checkbox is unchecked.

chrome/browser/resources/options/import_data_overlay.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.
 
 cr.define('options', function() {
   var OptionsPage = options.OptionsPage;
 
   /**
    * ImportDataOverlay class
    * Encapsulated handling of the 'Import Data' overlay page.
@@ skipping 68 matching lines @@
 
     /**
      * Sets the enabled and checked state of the commit button.
      * @private
      */
     validateCommitButton_: function() {
       var somethingToImport =
           $('import-history').checked || $('import-favorites').checked ||
           $('import-passwords').checked || $('import-search').checked;
       $('import-data-commit').disabled = !somethingToImport;
+      $('import-choose-file').disabled = !$('import-favorites').checked;
     },
 
     /**
      * Sets the enabled state of all the checkboxes and the commit button.
      * @private
      */
     setAllControlsEnabled_: function(enabled) {
       var checkboxes =
           document.querySelectorAll('#import-checkboxes input[type=checkbox]');
       for (var i = 0; i < checkboxes.length; i++)
@@ skipping 167 matching lines @@
     ImportDataOverlay.getInstance().validateCommitButton_();
 
     OptionsPage.navigateToPage('importData');
   };
 
   // Export
   return {
     ImportDataOverlay: ImportDataOverlay
   };
 });