Migrate async tests to strong

tests/lib_strong/async/catch_errors15_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 = [];
+
+  catchErrors(() {
+    events.add("catch error entry");
+    catchErrors(() {
+      events.add("catch error entry2");
+      new Future.error("future error");
+      new Future.error("future error2");
+      new Future.value(499).then((x) => throw x);
+      new Future.delayed(const Duration(milliseconds: 50), () {
+        throw "delayed error";
+      });
+      throw "catch error";
+    }).listen((x) {
+                events.add("i $x");
+                if (x == "delayed error") done.complete(true);
+              },
+              onDone: () { Expect.fail("Unexpected callback"); });
+    events.add("after inner");
+    throw "inner throw";
+  }).listen((x) {
+      events.add("o $x");
+    },
+    onDone: () { Expect.fail("Unexpected callback"); });
+  done.future.whenComplete(() {
+    // Give some time to run the handlers.
+    Timer.run(() {
+      Expect.listEquals(["catch error entry",
+                         "catch error entry2",
+                         "after inner",
+                         "main exit",
+                         "i catch error",
+                         // We guarantee the order of one stream but not any
+                         // global order.
+                         "o inner throw",
+                         "i future error",
+                         "i future error2",
+                         "i 499",
+                         "i delayed error",
+                         ],
+                         events);
+      asyncEnd();
+    });
+  });
+  events.add("main exit");
+}