Extend HttpBody handler to support 'multipart/form-data'.

sdk/lib/io/http_body.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;
 
 
 /**
  * [HttpBodyHandler] is a helper class for parsing and collecting HTTP message
  * data in an easy-to-use [HttpBody] object. The content body is parsed,
@@ skipping 56 matching lines @@
 
 /**
  * A HTTP content body produced by [HttpBodyHandler] for either [HttpRequest]
  * or [HttpClientResponse].
  */
 abstract class HttpBody {
   /**
    * The content type e.g. application/json, application/octet-stream,
    * application/x-www-form-urlencoded, text/plain.
    */
-  String get mimeType;
+  ContentType get contentType;
 
   /**
    * A high-level type value, that reflects how the body was parsed, e.g.
    * "text", "binary" and "json".
    */
   String get type;
 
   /**
    * The actual body. The type depends on [type].
    */
@@ skipping 48 matching lines @@
   /**
    * Returns the request headers.
    */
   HttpHeaders get headers;
 
   /**
    * The [HttpResponse] used for responding to the client.
    */
   HttpResponse get response;
 }
+
+
+/**
+ * A [HttpBodyFileUpload] object wraps a file upload, presenting a way for
+ * extracting filename, contentType and the data of the uploaded file.
+ */
+abstract class HttpBodyFileUpload {
+  /**
+   * The filename of the uploaded file.
+   */
+  String filename;
+
+  /**
+   * The [ContentType] of the uploaded file. For 'text/\*' and
+   * 'application/json' the [data] field will a String.
+   */
+  ContentType contentType;
+
+  /**
+   * The content of the file. Either a [String] or a [List<int>].
+   */
+  dynamic content;
+}