Fix build when ENABLE_MANAGED_USERS is not defined

chrome/browser/ui/webui/downloads_ui_browsertest.js

 // Copyright 2013 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.
 
 GEN('#include "chrome/browser/ui/webui/downloads_ui_browsertest.h"');
 
 /** @const */ var TOTAL_RESULT_COUNT = 25;
 
 /**
  * Test C++ fixture for downloads WebUI testing.
@@ skipping 143 matching lines @@
 };
 
 // Test UI when removing entries is prohibited.
 TEST_F('DownloadsWebUIDeleteProhibitedTest', 'DeleteProhibited', function() {
   this.testHelper(false, false);
   // TODO(pamg): Mock out the back-end calls, so we can also test removing a
   // single item.
   testDone();
 });
 
+GEN('#if defined(ENABLE_MANAGED_USERS)');
 /**
  * Fixture for Downloads WebUI testing for a supervised user.
  * @extends {BaseDownloadsWebUITest}
  * @constructor
  */
 function DownloadsWebUIForSupervisedUsersTest() {}
 
 DownloadsWebUIForSupervisedUsersTest.prototype = {
   __proto__: BaseDownloadsWebUITest.prototype,
 
   /** @override */
   typedefCppFixture: 'DownloadsWebUIForSupervisedUsersTest',
 };
 
 // Test UI for supervised users, removing entries should be disabled
 // and removal controls should be hidden.
 TEST_F('DownloadsWebUIForSupervisedUsersTest', 'SupervisedUsers', function() {
   this.testHelper(false, true);
   testDone();
 });
+GEN('#endif');