Fix HttpBodyHandler to handle missing mimeType.

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 29 matching lines @@
     return stream.fold(
         new _BufferList(),
         (buffer, data) {
           // TODO(ajohnsen): Add limit for POST data.
           buffer.add(data);
           return buffer;
         })
         .then((list) {
           dynamic content = list.readBytes();
           String type = "binary";
-          String mimeType = headers.contentType.toString();
+          ContentType contentType = headers.contentType;
+          if (contentType == null) {
+            return new _HttpBody(null, type, content);
+          }
           String asText(Encoding defaultEncoding) {
             var encoding;
-            var charset = headers.contentType.charset;
+            var charset = contentType.charset;
             if (charset != null) encoding = Encoding.fromName(charset);
             if (encoding == null) encoding = defaultEncoding;
             return _decodeString(content, encoding);
           }
-          switch (headers.contentType.primaryType) {
+          switch (contentType.primaryType) {
             case "text":
               type = "text";
               content = asText(Encoding.ASCII);
               break;
 
             case "application":
-              switch (headers.contentType.subType) {
+              switch (contentType.subType) {
                 case "json":
                   content = JSON.parse(asText(Encoding.UTF_8));
                   type = "json";
                   break;
 
                 default:
                   break;
               }
               break;
 
             default:
               break;
           }
-          return new _HttpBody(mimeType, type, content);
+          return new _HttpBody(contentType.mimeType, type, content);
         });
   }
 }
 
 class _HttpBody implements HttpBody {
   final String mimeType;
   final String type;
   final dynamic body;
 
   _HttpBody(String this.mimeType,
@@ skipping 20 matching lines @@
   final int statusCode;
   final String reasonPhrase;
   final HttpHeaders headers;
 
   _HttpClientResponseBody(HttpClientResponse response, HttpBody body)
       : super(body.mimeType, body.type, body.body),
         statusCode = response.statusCode,
         reasonPhrase = response.reasonPhrase,
         headers = response.headers;
 }