isolates refactor: this change introduces 'dart:isolate' as a library. This is a

samples/tests/samples/src/chat/ChatServerTest.dart

 // Copyright (c) 2011, 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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
 
 #library("chat_server_test.dart");
+#import("dart:isolate");
 #import("../../../../chat/http.dart");
 #import("../../../../../lib/json/json.dart");
 #import("../../../../chat/chat_server_lib.dart");
 
 
 // Message to start chat test client running in an isolate.
 class ChatTestClientStart {
   ChatTestClientStart(int this.totalClients,
                       int this.messagesToSend,
                       int this.messagesToReceive,
@@ skipping 300 matching lines @@
   TestMain testMain = new TestMain.start(10, 2);
 }
 
 
 void main() {
   testOneClient();
   testTwoClients();
   testTwoClientsMoreMessages();
   testTenClients();
 }