Fix HttpClientTest to use onData for reading out the data from the response stream.

tests/standalone/src/io/HttpClientTest.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");
 
 void testGoogle() {
   HttpClient client = new HttpClient();
   var conn = client.get('www.google.com', 80, '/');
 
   conn.onRequest = (HttpClientRequest request) {
     request.keepAlive = false;
     request.outputStream.close();
   };
   conn.onResponse = (HttpClientResponse response) {
     Expect.isTrue(response.statusCode < 500);
-    response.inputStream.onClosed = () {
+    response.inputStream.onData = () {
       response.inputStream.read();
     };
     response.inputStream.onClosed = () {
       client.shutdown();
     };
   };
 }
 
 void main() {
   testGoogle();
 }