Add error-page support in VirtualDirectory.

pkg/http_server/test/utils.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.
 
 library utils;
 
 import 'dart:async';
 import 'dart:io';
 
 
@@ skipping 19 matching lines @@
 
 
 Future<HttpHeaders> getHeaders(int port, String path) {
   return new HttpClient().get('localhost', port, path)
       .then((request) => request.close())
       .then((response) => response.drain().then(
           (_) => response.headers));
 }
 
 
+Future<String> getAsString(int port, String path) {
+  return new HttpClient().get('localhost', port, path)
+      .then((request) => request.close())
+      .then((response) => StringDecoder.decode(response));
+}
+
+
 const CERTIFICATE = "localhost_cert";
 
 
 setupSecure() {
   Path scriptDir = new Path(new Options().script).directoryPath;
   Path certificateDatabase = scriptDir.append('pkcert');
   SecureSocket.initialize(database: certificateDatabase.toNativePath(),
                           password: 'dartdart');
 }