Migrate async tests to strong

tests/lib_strong/async/zone_run_unary_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 'package:async_helper/async_helper.dart';
+import 'dart:async';
+
+main() {
+  Completer done = new Completer();
+  List events = [];
+
+  bool shouldForward = true;
+  Expect.identical(Zone.ROOT, Zone.current);
+  Zone forked = Zone.current.fork(specification: new ZoneSpecification(
+      runUnary: (Zone self, ZoneDelegate parent, Zone origin, f(arg), arg) {
+        // The zone is still the same as when origin.run was invoked, which
+        // is the root zone. (The origin zone hasn't been set yet).
+        Expect.identical(Zone.current, Zone.ROOT);
+        events.add("forked.run1");
+        if (shouldForward) return parent.runUnary(origin, f, arg + 1);
+        return 42;
+      }));
+
+  events.add("zone forked");
+  Zone expectedZone = forked;
+  var result = forked.runUnary((arg) {
+    Expect.identical(expectedZone, Zone.current);
+    events.add("run closure");
+    return arg + 3;
+  }, 495);
+  Expect.equals(499, result);
+  events.add("executed run");
+
+  shouldForward = false;
+  result = forked.runUnary((arg) {
+    Expect.fail("should not be invoked");
+  }, 99);
+  Expect.equals(42, result);
+  events.add("executed run2");
+
+  asyncStart();
+  shouldForward = true;
+  result = forked.runUnary((arg) {
+    Expect.identical(forked, Zone.current);
+    events.add("run closure 2");
+    scheduleMicrotask(() {
+      events.add("run closure 3");
+      Expect.identical(forked, Zone.current);
+      done.complete(true);
+    });
+    return -arg - 8;
+  }, 490);
+  events.add("after nested scheduleMicrotask");
+  Expect.equals(-499, result);
+
+  done.future.whenComplete(() {
+    Expect.listEquals(
+        ["zone forked", "forked.run1", "run closure", "executed run",
+         "forked.run1", "executed run2", "forked.run1", "run closure 2",
+          "after nested scheduleMicrotask", "run closure 3"],
+        events);
+    asyncEnd();
+  });
+}