Implement support for application/x-www-form-urlencoded' form data in HttpBodyHandler.

sdk/lib/io/http_body_impl.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.
 
 part of dart.io;
 
 class _HttpBodyHandlerTransformer
     extends StreamEventTransformer<HttpRequest, HttpRequestBody> {
   void handleData(HttpRequest request, EventSink<HttpRequestBody> sink) {
     HttpBodyHandler.processRequest(request)
@@ skipping 92 matching lines @@
         return asText(Encoding.ASCII);
 
       case "application":
         switch (contentType.subType) {
           case "json":
             return asText(Encoding.UTF_8)
                 .then((body) => new _HttpBody(contentType,
                                               "json",
                                               JSON.parse(body.body)));
 
+          case "x-www-form-urlencoded":
+            return asText(Encoding.ASCII)
+                .then((body) {
+                  var map = _HttpUtils.splitQueryString(body.body);
+                  var result = {};
+                  String parse(String s) {
+                    return _HttpUtils.decodeHttpEntityString(
+                        _HttpUtils.decodeUrlEncodedString(s));
+                  }
+                  for (var key in map.keys) {
+                    result[parse(key)] = parse(map[key]);
+                  }
+                  return new _HttpBody(contentType, "form", result);
+                });
+
           default:
             break;
         }
         break;
 
       case "multipart":
         switch (contentType.subType) {
           case "form-data":
             return asFormData();
 
@@ skipping 48 matching lines @@
   _HttpClientResponseBody(HttpClientResponse response, HttpBody body)
       : super(body.contentType, body.type, body.body),
         this.response = response;
 
   int get statusCode => response.statusCode;
 
   String get reasonPhrase => response.reasonPhrase;
 
   HttpHeaders get headers => response.headers;
 }