Migrate async tests to strong

tests/lib_strong/async/catch_errors8_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 nested `catchErrors`.
+  // The nested `catchErrors` throws all kinds of different errors (synchronous
+  // and asynchronous). The body of the outer `catchErrors` furthermore has a
+  // synchronous `throw`.
+  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(x);
+      if (x == "delayed error") {
+        throw "inner done throw";
+      }
+    });
+    events.add("after inner");
+    throw "inner throw";
+  }).listen((x) {
+      events.add(x);
+      if (x == "inner done throw") {
+        done.complete(true);
+      }
+    },
+    onDone: () { Expect.fail("Unexpected callback"); });
+
+  done.future.whenComplete(() {
+    Expect.listEquals(["catch error entry",
+                        "catch error entry2",
+                        "after inner",
+                        "main exit",
+                        "catch error",
+                        "inner throw",
+                        "future error",
+                        "future error2",
+                        499,
+                        "delayed error",
+                        "inner done throw"
+                        ],
+                        events);
+    asyncEnd();
+  });
+  events.add("main exit");
+}