Expose the HttpRequest object in HttpRequestBody, making all request properties available.

pkg/http_server/test/http_body_test.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.
 
 import 'dart:io';
 import 'dart:convert';
 
 import 'package:http_server/http_server.dart';
 import 'package:unittest/unittest.dart';
 
@@ skipping 76 matching lines @@
             String type,
             {bool shouldFail: false,
              Encoding defaultEncoding: UTF8}) {
     HttpServer.bind("127.0.0.1", 0).then((server) {
       server.transform(new HttpBodyHandler(defaultEncoding: defaultEncoding))
           .listen((body) {
             expect(shouldFail, isFalse);
             expect(body.type, equals(type));
             switch (type) {
               case "text":
-                expect(body.contentType.mimeType, equals("text/plain"));
+                expect(body.request.headers.contentType.mimeType,
+                       equals("text/plain"));
                 expect(body.body, equals(expectedBody));
                 break;
 
               case "json":
-                expect(body.contentType.mimeType, equals("application/json"));
+                expect(body.request.headers.contentType.mimeType,
+                       equals("application/json"));
                 expect(body.body, equals(expectedBody));
                 break;
 
               case "binary":
-                expect(body.contentType, isNull);
+                expect(body.request.headers.contentType, isNull);
                 expect(body.body, equals(expectedBody));
                 break;
 
               case "form":
-                var mimeType = body.contentType.mimeType;
+                var mimeType = body.request.headers.contentType.mimeType;
                 expect(mimeType,
                        anyOf(equals('multipart/form-data'),
                              equals('application/x-www-form-urlencoded')));
                 expect(body.body.keys.toSet(),
                        equals(expectedBody.keys.toSet()));
                 for (var key in expectedBody.keys) {
                   var found = body.body[key];
                   var expected = expectedBody[key];
                   if (found is HttpBodyFileUpload) {
                     expect(found.contentType.toString(),
                            equals(expected['contentType']));
                     expect(found.filename,
                            equals(expected['filename']));
                     expect(found.content,
                            equals(expected['content']));
                   } else {
                     expect(found, equals(expected));
                   }
                 }
                 break;
 
               default:
                 throw "bad body type";
             }
-            body.response.close();
+            body.request.response.close();
           }, onError: (error) {
             if (!shouldFail) throw error;
           });
 
       var client = new HttpClient();
       client.post("127.0.0.1", server.port, "/")
           .then((request) {
             if (mimeType != null) {
               request.headers.contentType =
                   ContentType.parse(mimeType);
@@ skipping 176 matching lines @@
   test('application/x-www-form-urlencoded',
        'name=%C8%A4%C8%A4'.codeUnits,
        { 'name' : 'ȤȤ' },
        "form");
 }
 
 void main() {
   testHttpClientResponseBody();
   testHttpServerRequestBody();
 }