Migrated test block 170 to Dart 2.0.

tests/lib_strong/async/intercept_schedule_microtask3_test.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// 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.
-
-import 'package:async_helper/async_helper.dart';
-import "package:expect/expect.dart";
-import 'dart:async';
-import 'catch_errors.dart';
-
-var events = [];
-
-body() {
-  events.add("body entry");
-  scheduleMicrotask(() {
-    events.add("run async body");
-  });
-  return 499;
-}
-
-handler(fun) {
-  events.add("handler");
-  scheduleMicrotask(fun);
-  events.add("handler done");
-}
-
-main() {
-  asyncStart();
-
-  // Test that scheduleMicrotask inside the scheduleMicrotask-handler goes to
-  // the parent zone.
-  var result = runZonedScheduleMicrotask(body, onScheduleMicrotask: handler);
-  events.add("after");
-  scheduleMicrotask(() {
-    Expect.listEquals(
-        ["body entry", "handler", "handler done", "after", "run async body"],
-        events);
-    asyncEnd();
-  });
-}