Sharing metatest logic between unittest and scheduled_test

pkg/scheduled_test/test/scheduled_test/timeout_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:scheduled_test/scheduled_test.dart';
 import 'package:scheduled_test/src/mock_clock.dart' as mock_clock;
 
-import '../metatest.dart';
+import 'package:metatest/metatest.dart';
 import '../utils.dart';
 
-void main(_, message) {
+void main() => initTests(_test);
+
+void _test(message) {
   initMetatest(message);
 
   setUpTimeout();
 
   expectTestsPass("a single task that takes too long will cause a timeout "
       "error", () {
     mock_clock.mock().run();
     var errors;
     test('test 1', () {
       currentSchedule.timeout = new Duration(milliseconds: 1);
@@ skipping 170 matching lines @@
           currentSchedule.heartbeat();
           return sleep(2);
         });
       });
     });
   });
 
   // TODO(nweiz): test out-of-band post-timeout errors that are detected after
   // the test finishes once we can detect top-level errors (issue 8417).
 }