Migrated test block 170 to Dart 2.0.

tests/lib/async/print_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.
-
-// This test tests a core-library property, but uses zones to do this.
-// Verifies that print(x) works with bad toString methods.
-
-import 'dart:async';
-import 'package:expect/expect.dart';
-
-class A {
-  toString() {
-    if (false
-          || true // //# 01: runtime error
-        ) {
-      return 499;
-    } else {
-      return "ok";
-    }
-  }
-}
-
-void interceptedPrint(self, parent, zone, message) {
-  Expect.isTrue(message is String);
-}
-
-main() {
-  runZoned(() {
-    print(new A());
-  }, zoneSpecification: new ZoneSpecification(print: interceptedPrint));
-}