Clean up some pub and scheduled_test integration with the new isolate API.

pkg/scheduled_test/test/descriptor/directory_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 'dart:async';
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
 import 'package:scheduled_test/descriptor.dart' as d;
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../metatest.dart';
 import 'utils.dart';
 
-void main(List<String> args, message) {
-  metaTestInit(message);
+void main(_, message) {
+  initMetatest(message);
 
   setUpTimeout();
 
   expectTestsPass("directory().create() creates a directory and its contents",
       () {
     test('test', () {
       scheduleSandbox();
 
       d.dir('dir', [
         d.dir('subdir', [
@@ skipping 377 matching lines @@
     });
   });
 
   expectTestsPass("directory().describe() with no contents returns the "
       "directory name", () {
     test('test', () {
       expect(d.dir('dir').describe(), equals('dir'));
     });
   });
 }