Add encoding tests to pkg/http.

pkg/http/lib/src/request.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 request;
 
 import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';
 
@@ skipping 103 matching lines @@
   /// `application/x-www-form-urlencoded`.
   ///
   /// This map should only be set, not modified in place.
   Map<String, String> get bodyFields {
     if (_contentType == null ||
         _contentType.value != "application/x-www-form-urlencoded") {
       throw new StateError('Cannot access the body fields of a Request without '
           'content-type "application/x-www-form-urlencoded".');
     }
 
-    return queryToMap(body);
+    return queryToMap(body, encoding: encoding);
   }
 
   set bodyFields(Map<String, String> fields) {
     if (_contentType == null) {
       _contentType = new ContentType("application", "x-www-form-urlencoded");
     } else if (_contentType.value != "application/x-www-form-urlencoded") {
       throw new StateError('Cannot set the body fields of a Request with '
           'content-type "${_contentType.value}".');
     }
 
-    this.body = mapToQuery(fields);
+    this.body = mapToQuery(fields, encoding: encoding);
   }
 
   /// Creates a new HTTP request.
   Request(String method, Uri url)
     : super(method, url),
       _defaultEncoding = UTF8,
       _bodyBytes = new Uint8List(0);
 
   /// Freezes all mutable fields and returns a single-subscription [ByteStream]
   /// containing the request body.
@@ skipping 13 matching lines @@
   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.");
   }
 }