Remove stale files from lib/html/src.

lib/html/src/SVGDocument.dart

Index: lib/html/src/SVGDocument.dart
diff --git a/lib/html/src/SVGDocument.dart b/lib/html/src/SVGDocument.dart
deleted file mode 100644
index 14d3dd1a08c62751cd38bbc2879237aab1c4b1c2..0000000000000000000000000000000000000000
--- a/lib/html/src/SVGDocument.dart
+++ /dev/null
@@ -1,8 +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.
-
-// WARNING: Do not edit - generated code.
-
-interface SVGDocument extends Document {
-}