Revert revision 11570, this still has dartium failures.

lib/dom/src/dart2js_FactoryProviders.dart

Index: lib/dom/src/dart2js_FactoryProviders.dart
===================================================================
--- lib/dom/src/dart2js_FactoryProviders.dart	(revision 11575)
+++ lib/dom/src/dart2js_FactoryProviders.dart	(working copy)
@@ -10,15 +10,6 @@
 ''';
 }
 
-class _FormDataFactoryProvider {
-
-  factory FormData([HTMLFormElement form = null]) native '''
-    if (form == null) return new FormData();
-    return new FormData(form);
-  ''';
-
-}
-
 class _WebKitPointFactoryProvider {
 
   factory WebKitPoint(num x, num y) native '''return new WebKitPoint(x, y);''';