Use patching for dart:io.

lib/io/http_parser.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.
 
 // Global constants.
 class _Const {
   // Bytes for "HTTP".
   static const HTTP = const [72, 84, 84, 80];
   // Bytes for "HTTP/1.".
   static const HTTP1DOT = const [72, 84, 84, 80, 47, 49, 46];
@@ skipping 713 matching lines @@
   Function dataEnd;
   Function error;
 }
 
 
 class HttpParserException implements Exception {
   const HttpParserException([String this.message = ""]);
   String toString() => "HttpParserException: $message";
   final String message;
 }