TEst to reproduce issue 18747

pkg/web_components/test/location_wrapper_test.dart

Index: pkg/web_components/test/location_wrapper_test.dart
diff --git a/tests/html/mouse_event_test.dart b/pkg/web_components/test/location_wrapper_test.dart
similarity index 71%
copy from tests/html/mouse_event_test.dart
copy to pkg/web_components/test/location_wrapper_test.dart
index dcd442ff833f063a219cc9beb170173611f455bd..a1c531ad50b6d1fa0737f10aa73ee0533142899d 100644
--- a/tests/html/mouse_event_test.dart
+++ b/pkg/web_components/test/location_wrapper_test.dart
@@ -2,16 +2,16 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library mouse_event_test;
-import 'package:unittest/unittest.dart';
-import 'package:unittest/html_config.dart';
+library template_wrappers_test;
+
 import 'dart:html';
+import 'package:unittest/html_config.dart';
+import 'package:unittest/unittest.dart';
 
 main() {
   useHtmlConfiguration();
 
-  test('relatedTarget', () {
-    var event = new MouseEvent('mouseout');
-    expect(event.relatedTarget, isNull);
+  test('OK to access location with platform.js', () {
+    expect(window.location.toString(), window.location.href);
   });
 }