Migrate async tests to strong

tests/lib_strong/async/catch_errors11_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';
+
+main() {
+  asyncStart();
+  Completer done = new Completer();
+
+  var events = [];
+  // Test that `catchErrors` catches errors that are delayed by `Timer.run`.
+  catchErrors(() {
+    events.add("catch error entry");
+    new Future.error("future error");
+    Timer.run(() {
+      done.complete(true);
+      throw "timer error";
+    });
+  }).listen((x) {
+      events.add(x);
+    },
+    onDone: () { Expect.fail("Unexpected callback"); });
+
+  done.future.whenComplete(() {
+    // Give the handler time to execute.
+    Timer.run(() {
+      Expect.listEquals([
+                         "catch error entry",
+                         "main exit",
+                         "future error",
+                         "timer error",
+                         ],
+                         events);
+      asyncEnd();
+    });
+  });
+  events.add("main exit");
+}