Big merge from experimental to bleeding edge.

sdk/lib/isolate/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.
-
-part of dart.isolate;
-
-abstract class Timer {
-  /**
-   * Creates a new timer. The [callback] callback is invoked after
-   * [milliseconds] milliseconds.
-   */
-  external factory Timer(int milliseconds, void callback(Timer timer));
-
-  /**
-   * Creates a new repeating timer. The [callback] is invoked every
-   * [milliseconds] millisecond until cancelled.
-   */
-  external factory Timer.repeating(int milliseconds,
-                                   void callback(Timer timer));
-
-  /**
-   * Cancels the timer.
-   */
-  void cancel();
-}