Remove stale files from lib/html/src.

lib/html/src/XMLHttpRequestUpload.dart

Index: lib/html/src/XMLHttpRequestUpload.dart
diff --git a/lib/html/src/XMLHttpRequestUpload.dart b/lib/html/src/XMLHttpRequestUpload.dart
deleted file mode 100644
index a0a0c0a8db754d436372619cc6a8d85e89f20bea..0000000000000000000000000000000000000000
--- a/lib/html/src/XMLHttpRequestUpload.dart
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright (c) 2011, 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.
-
-interface XMLHttpRequestUploadEvents extends Events {
-  EventListenerList get abort();
-  EventListenerList get error();
-  EventListenerList get load();
-  EventListenerList get loadStart();
-  EventListenerList get progress();
-}
-
-interface XMLHttpRequestUpload extends EventTarget {
-  XMLHttpRequestUploadEvents get on();
-}