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

BUG=275343
TEST=open chrome, navigate to chrome://settings/importData, select the
bookmarks option from the combobox, uncheck the "Favorites" checkbox, observe
that the "Choose ..." button isn't enabled anymore, check it, it becomes enabled
again.
R=dubroy@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23717032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@221923 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/options/import_data_overlay.js

@@ -86,6 +86,7 @@ cr.define('options', function() {
           $('import-history').checked || $('import-favorites').checked ||
           $('import-passwords').checked || $('import-search').checked;
       $('import-data-commit').disabled = !somethingToImport;
+      $('import-choose-file').disabled = !$('import-favorites').checked;
     },
 
     /**