Fix typo in failure-branch of stream iterator test.

tests/lib/async/stream_iterator_test.dart

 // Copyright (c) 2013, 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.
 
 import "dart:async";
 import "package:unittest/unittest.dart";
 
 main() {
   test("stream iterator basic", () {
     StreamController c = new StreamController();
@@ skipping 37 matching lines @@
 
   test("stream iterator error", () {
     StreamController c = new StreamController();
     Stream s = c.stream;
     StreamIterator i = new StreamIterator(s);
     i.moveNext().then(expectAsync1((bool b) {
       expect(b, isTrue);
       expect(42, i.current);
       return i.moveNext();
     })).then((bool b) {
-      Expect.fail("Result not expected");
+      fail("Result not expected");
     }, onError: expectAsync1((e) {
       expect("BAD", e);
       return i.moveNext();
     })).then(expectAsync1((bool b) {
       expect(b, isFalse);
     }));
     c.add(42);
     c.addError("BAD");
     c.add(37);
     c.close();
@@ skipping 16 matching lines @@
     })).then(expectAsync1((bool b) {
       expect(b, isTrue);
       expect(37, i.current);
       return i.moveNext();
     })).then(expectAsync1((bool b) {
       expect(b, isFalse);
     }));
     c.add(42);
   });
 }