Rework Timer interface.

runtime/lib/timer_patch.dart

Index: runtime/lib/timer_patch.dart
diff --git a/runtime/lib/timer_patch.dart b/runtime/lib/timer_patch.dart
index d27e4e88994504df4b199b2a7e9d973dfb1d58de..10249155da61ce0dff3c0c4a5f3f0b5630cf1965 100644
--- a/runtime/lib/timer_patch.dart
+++ b/runtime/lib/timer_patch.dart
@@ -2,23 +2,40 @@
 // 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);
   }
 }