Big merge from experimental to bleeding edge.

runtime/lib/timer_patch.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.
+
+patch class Timer {
+  /* patch */ factory Timer(int milliseconds, void callback(Timer timer)) {
+    if (_TimerFactory._factory == null) {
+      throw new UnsupportedError("Timer interface not supported.");
+    }
+    return _TimerFactory._factory(milliseconds, callback, false);
+  }
+
+  /**
+   * Creates a new repeating timer. The [callback] is invoked every
+   * [milliseconds] millisecond until cancelled.
+   */
+  /* patch */ factory Timer.repeating(int milliseconds,
+                                      void callback(Timer timer)) {
+    if (_TimerFactory._factory == null) {
+      throw new UnsupportedError("Timer interface not supported.");
+    }
+    return _TimerFactory._factory(milliseconds, callback, true);
+  }
+}
+
+typedef Timer _TimerFactoryClosure(int milliseconds,
+                                   void callback(Timer timer),
+                                   bool repeating);
+
+class _TimerFactory {
+  static _TimerFactoryClosure _factory;
+}
+
+// TODO(ahe): Warning: this is NOT called by Dartium. Instead, it sets
+// [_TimerFactory._factory] directly.
+void _setTimerFactoryClosure(_TimerFactoryClosure closure) {
+  _TimerFactory._factory = closure;
+}