Revert the revert of http://code.google.com/p/dart/source/detail?r=3360.

compiler/lib/implementation/type_token.dart

Index: compiler/lib/implementation/type_token.dart
diff --git a/compiler/lib/implementation/type_token.dart b/compiler/lib/implementation/type_token.dart
deleted file mode 100644
index 6d12be7afb94ccc895abe4e934ebc3b8ef4242f0..0000000000000000000000000000000000000000
--- a/compiler/lib/implementation/type_token.dart
+++ /dev/null
@@ -1,11 +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.
-
-/*
- * This class is generic. It's main use is to transfer type information from
- * Dart to JS.
- */
-class TypeToken<T> {
-  const TypeToken();
-}