Change Future.delayed to take a Duration.

tests/standalone/io/fuzz_support.dart

Index: tests/standalone/io/fuzz_support.dart
diff --git a/tests/standalone/io/fuzz_support.dart b/tests/standalone/io/fuzz_support.dart
index 4c7cd1cd3990767b79e0bc106154bed7b3b24ae7..e6caa12dfc83edea89031e4f18528534d5e6492f 100644
--- a/tests/standalone/io/fuzz_support.dart
+++ b/tests/standalone/io/fuzz_support.dart
@@ -49,5 +49,7 @@ doItSync(Function f) {
 // completion.
 Future doItAsync(void f()) {
   // Ignore value and errors.
-  return new Future.delayed(0, f).catchError((_) {}).then((_) => true);
+  return new Future.delayed(Duration.ZERO, f)
+    .catchError((_) {})
+    .then((_) => true);
 }