Update pkg/http to use the new async APIs.

pkg/http/lib/src/request.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.
 
 library request;
 
+import 'dart:async';
 import 'dart:io';
 import 'dart:scalarlist';
 import 'dart:uri';
 
 import 'base_request.dart';
+import 'byte_stream.dart';
 import 'utils.dart';
 
 /// An HTTP request where the entire request body is known in advance.
 class Request extends BaseRequest {
   /// The size of the request body, in bytes. This is calculated from
   /// [bodyBytes].
   ///
   /// The content length cannot be set for [Request], since it's automatically
   /// calculated from [bodyBytes].
   int get contentLength => bodyBytes.length;
@@ skipping 102 matching lines @@
 
     this.body = mapToQuery(fields);
   }
 
   /// Creates a new HTTP request.
   Request(String method, Uri url)
     : super(method, url),
       _defaultEncoding = Encoding.UTF_8,
       _bodyBytes = new Uint8List(0);
 
-  /// Freeze all mutable fields and return an [InputStream] containing the
-  /// request body.
-  InputStream finalize() {
+  /// Freezes all mutable fields and returns a single-subscription [ByteStream]
+  /// containing the request body.
+  ByteStream finalize() {
     super.finalize();
-
-    var stream = new ListInputStream();
-    stream.write(bodyBytes);
-    stream.markEndOfStream();
-    return stream;
+    return new ByteStream.fromBytes(bodyBytes);
   }
 
   /// The `Content-Type` header of the request (if it exists) as a
   /// [ContentType].
   ContentType get _contentType {
     var contentType = headers[HttpHeaders.CONTENT_TYPE];
     if (contentType == null) return null;
     return new ContentType.fromString(contentType);
   }
 
   set _contentType(ContentType value) {
     headers[HttpHeaders.CONTENT_TYPE] = value.toString();
   }
 
   /// Throw an error if this request has been finalized.
   void _checkFinalized() {
     if (!finalized) return;
     throw new StateError("Can't modify a finalized Request.");
   }
 }