- Move the Timer interface to the dart:isolate library so that it

lib/isolate/timer.dart

Index: lib/isolate/timer.dart
===================================================================
--- lib/isolate/timer.dart	(revision 0)
+++ lib/isolate/timer.dart	(revision 0)
@@ -0,0 +1,22 @@
+// 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.
+
+interface Timer default _TimerFactory {
+  /**
+   * Creates a new timer. The [callback] callback is invoked after
+   * [milliSeconds] milliseconds.
+   */
+  Timer(int milliSeconds, void callback(Timer timer));
+
+  /**
+   * Creates a new repeating timer. The [callback] is invoked every
+   * [milliSeconds] millisecond until cancelled.
+   */
+  Timer.repeating(int milliSeconds, void callback(Timer timer));
+
+  /**
+   * Cancels the timer.
+   */
+  void cancel();
+}