Remove lib/dom directory!

lib/dom/src/Timer.dart

-// 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.
-
-// TODO(antonm): support not DOM isolates too.
-class _Timer implements Timer {
-  final canceller;
-
-  _Timer(this.canceller);
-
-  void cancel() { canceller(); }
-}
-
-get _timerFactoryClosure => (int milliSeconds, void callback(Timer timer), bool repeating) {
-  var maker;
-  var canceller;
-  if (repeating) {
-    maker = window.setInterval;
-    canceller = window.clearInterval;
-  } else {
-    maker = window.setTimeout;
-    canceller = window.clearTimeout;
-  }
-  Timer timer;
-  final int id = maker(() { callback(timer); }, milliSeconds);
-  timer = new _Timer(() { canceller(id); });
-  return timer;
-};