Use the new test runner.

test/dart2js/source_maps_include_core_libs_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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 '../descriptor.dart' as d;
 import '../test_pub.dart';
 
 main() {
-  initConfig();
-
   // This test is a bit shaky. Since dart2js is free to inline things, it's
   // not precise as to which source libraries will actually be referenced in
   // the source map. But this tries to use a type in the core library
   // (Duration) and validate that its source ends up in the source map.
   integration("Dart core libraries are available to source maps", () {
     d.dir(appPath, [
       d.appPubspec(),
       d.dir("web", [
         d.file("main.dart", "main() => new Duration().toString();"),
         d.dir("sub", [
@@ skipping 23 matching lines @@
                       contains("class Duration"))
                 ])
               ])
             ])
           ])
         ])
       ])
     ]).validate();
   });
 }