Migrate async tests to strong

tests/lib_strong/async/zone_future_schedule_microtask_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:expect/expect.dart";
+import 'dart:async';
+import 'package:async_helper/async_helper.dart';
+import 'catch_errors.dart';
+
+main() {
+  asyncStart();
+  Completer done = new Completer();
+
+  // Make sure that the zones use the scheduleMicrotask of their zones.
+  int scheduleMicrotaskCount = 0;
+  Completer completer;
+  Completer completer2;
+  Future future;
+  Future future2;
+  runZonedScheduleMicrotask(() {
+    completer = new Completer();
+    completer.complete(499);
+    completer2 = new Completer.sync();
+    completer2.complete(-499);
+    future = new Future.value(42);
+    future2 = new Future.error(11);
+  }, onScheduleMicrotask: (f) {
+    scheduleMicrotaskCount++;
+    scheduleMicrotask(f);
+  });
+  int openCallbackCount = 0;
+
+  openCallbackCount++;
+  completer.future.then((x) {
+    Expect.equals(499, x);
+    openCallbackCount--;
+    if (openCallbackCount == 0) done.complete();
+  });
+
+  openCallbackCount++;
+  completer2.future.then((x) {
+    Expect.equals(-499, x);
+    openCallbackCount--;
+    if (openCallbackCount == 0) done.complete();
+  });
+
+  openCallbackCount++;
+  future.then((x) {
+    Expect.equals(42, x);
+    openCallbackCount--;
+    if (openCallbackCount == 0) done.complete();
+  });
+
+  openCallbackCount++;
+  future2.catchError((x) {
+    Expect.equals(11, x);
+    openCallbackCount--;
+    if (openCallbackCount == 0) done.complete();
+  });
+
+  done.future.whenComplete(() {
+    Expect.equals(4, scheduleMicrotaskCount);
+    asyncEnd();
+  });
+}