Fix a broken scheduled_test test.

pkg/scheduled_test/test/scheduled_test/nested_task_test.dart

Index: pkg/scheduled_test/test/scheduled_test/nested_task_test.dart
diff --git a/pkg/scheduled_test/test/scheduled_test/nested_task_test.dart b/pkg/scheduled_test/test/scheduled_test/nested_task_test.dart
index ecb88d09175f4b5229f898e52081ef2e5077bf5b..1356b80a76f57bdc4ffb1d5696f8b9cae5967bcd 100644
--- a/pkg/scheduled_test/test/scheduled_test/nested_task_test.dart
+++ b/pkg/scheduled_test/test/scheduled_test/nested_task_test.dart
@@ -90,7 +90,7 @@ void main(_, message) {
 
   expectTestsPass("nested scheduled blocks whose return values are passed to "
       "wrapFuture should report exceptions once", () {
-    var error = new Object();
+    var error = 'oh no!';
     var errors;
     test('test 1', () {
       currentSchedule.onException.schedule(() {