Upgrading tests with unittest deprecations

tests/lib/async/timer_test.dart

Index: tests/lib/async/timer_test.dart
diff --git a/tests/lib/async/timer_test.dart b/tests/lib/async/timer_test.dart
index 057d3a7ee117ab621f7ed329126a480c61c18113..c25ce141be1f133c2129896fd15b9a9220608e35 100644
--- a/tests/lib/async/timer_test.dart
+++ b/tests/lib/async/timer_test.dart
@@ -28,7 +28,7 @@ void timeoutHandler() {
     timeout = timeout - DECREASE;
     Duration duration = new Duration(milliseconds: timeout);
     startTime = (new DateTime.now()).millisecondsSinceEpoch;
-    new Timer(duration, expectAsync0(timeoutHandler));
+    new Timer(duration, expectAsync(timeoutHandler));
   }
 }
 
@@ -38,6 +38,6 @@ main() {
     timeout = STARTTIMEOUT;
     Duration duration = new Duration(milliseconds: timeout);
     startTime = (new DateTime.now()).millisecondsSinceEpoch;
-    new Timer(duration, expectAsync0(timeoutHandler));
+    new Timer(duration, expectAsync(timeoutHandler));
   });
 }