Provide a constructor for (DOM)FormData, and rename to the more standard name,

lib/dom/dom.dart

Index: lib/dom/dom.dart
===================================================================
--- lib/dom/dom.dart	(revision 11420)
+++ lib/dom/dom.dart	(working copy)
@@ -69,6 +69,13 @@
 // 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.
 
+class _FormDataFactoryProvider {
+  factory FormData([FormElement form]) => _dummy();
+}
+// Copyright (c) 2012, 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.
+
 class _HTMLAudioElementFactoryProvider {
   factory HTMLAudioElement([String src]) => _dummy();
 }
@@ -1532,19 +1539,6 @@
 
 // WARNING: Do not edit - generated code.
 
-interface FormData {
-
-  void append(String name, String value, String filename);
-}
-
-interface DOMFormData extends FormData {
-}
-// Copyright (c) 2012, 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.
-
-// WARNING: Do not edit - generated code.
-
 interface DOMImplementation {
 
   CSSStyleSheet createCSSStyleSheet(String title, String media);
@@ -3163,6 +3157,18 @@
 
 // WARNING: Do not edit - generated code.
 
+interface FormData default _FormDataFactoryProvider {
+
+  FormData([FormElement form]);
+
+  void append(String name, String value, String filename);
+}
+// Copyright (c) 2012, 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.
+
+// WARNING: Do not edit - generated code.
+
 interface Gamepad {
 
   final List<num> axes;