Rework Timer interface.

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.
 
+typedef void _TimerCallback0();
+typedef void _TimerCallback1(Timer timer);
+
 patch class Timer {
-  /* patch */ factory Timer(int milliseconds, void callback(Timer timer)) {
+  /* patch */ factory Timer(var duration, Function callback) {
+    // TODO(floitsch): remove these checks when we remove the deprecated
+    // millisecond argument and the 1-argument callback. Also remove
+    // the int-test below.
+    if (callback is! _TimerCallback0 && callback is! _TimerCallback1) {
+      throw new ArgumentError(callback);
+    }
+    int milliseconds = duration is int ? duration : duration.inMilliseconds;
+    if (milliseconds < 0) milliseconds = 0;
+    _TimerCallback1 oneArgumentCallback =
+        callback is _TimerCallback1 ? callback : (_) { callback(); };
     if (_TimerFactory._factory == null) {
       throw new UnsupportedError("Timer interface not supported.");
     }
-    return _TimerFactory._factory(milliseconds, callback, false);
+    return _TimerFactory._factory(milliseconds, oneArgumentCallback, false);
   }
 
   /**
    * Creates a new repeating timer. The [callback] is invoked every
    * [milliseconds] millisecond until cancelled.
    */
-  /* patch */ factory Timer.repeating(int milliseconds,
+  /* patch */ factory Timer.repeating(var duration,
                                       void callback(Timer timer)) {
     if (_TimerFactory._factory == null) {
       throw new UnsupportedError("Timer interface not supported.");
     }
+    // TODO(floitsch): remove this check when we remove the deprecated
+    // millisecond argument.
+    int milliseconds = duration is int ? duration : duration.inMilliseconds;
+    if (milliseconds < 0) milliseconds = 0;
     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;
 }