Generate an error for active connections when the HTTP client is shutdown

tests/standalone/io/http_server_handler_test.dart

 // Copyright (c) 2012, 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:io';
 import 'dart:isolate';
 
 class Handler1 {
   void onRequest(HttpRequest request, HttpResponse response) {
@@ skipping 83 matching lines @@
     conn.onResponse = (HttpClientResponse response) {
       Expect.equals(HttpStatus.NOT_FOUND, response.statusCode);
       Expect.equals("Nicht Gefunden", response.reasonPhrase);
 
       // Install another default handler.
       server.defaultHandler = new French404Handler();
       HttpClientConnection conn = client.get("127.0.0.1", server.port, "/");
       conn.onResponse = (HttpClientResponse response) {
         Expect.equals(HttpStatus.NOT_FOUND, response.statusCode);
         Expect.equals("Non Trouvé", response.reasonPhrase);
-        done();
+        response.inputStream.onClosed = done;
       };
       conn.onError = error;
     };
     conn.onError = error;
   };
   conn.onError = error;
 }
 
 void testHandlers() {
   Server server = new Server();
@@ skipping 63 matching lines @@
   testRequest("/yyy.dat", HttpStatus.OK, "Handler 3");
   testRequest("/abc.dat", HttpStatus.OK, "Handler 4");
   testRequest("/abcdat", HttpStatus.NOT_FOUND, "");
   testRequest("/xxx.dat", HttpStatus.OK, "Handler 2");
 }
 
 main() {
   testDefaultHandler();
   testHandlers();
 }