Rework Timer interface.

tests/lib/async/slow_consumer_test.dart

Index: tests/lib/async/slow_consumer_test.dart
diff --git a/tests/lib/async/slow_consumer_test.dart b/tests/lib/async/slow_consumer_test.dart
index 027924eb393c0212dbd780bc2387049c82e3c646..dcc616714ad9d1dc449f2a42e54780daa5901cf9 100644
--- a/tests/lib/async/slow_consumer_test.dart
+++ b/tests/lib/async/slow_consumer_test.dart
@@ -50,7 +50,7 @@ class DataProvider {
 
   DataProvider(int this.bytesPerSecond, int this.targetCount, this.chunkSize) {
     controller = new StreamController(onPauseStateChange: onPauseStateChange);
-    new Timer(0, (_) => send());
+    Timer.run(send);
   }
 
   Stream get stream => controller.stream;
@@ -69,7 +69,8 @@ class DataProvider {
     }
     controller.add(new List.fixedLength(listSize));
     int ms = listSize * 1000 ~/ bytesPerSecond;
-    if (!controller.isPaused) new Timer(ms, (_) => send());
+    Duration duration = new Duration(milliseconds: ms);
+    if (!controller.isPaused) new Timer(duration, send);
   }
 
   onPauseStateChange() {