Fix some tests.

tests/compiler/dart2js/simple_inferrer_closure_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 'package:expect/expect.dart';
 import 'compiler_helper.dart';
 
 const String TEST = """
 returnInt1() {
   var a = 42;
   var f = () {
     return a;
   };
   return a;
 }
@@ skipping 79 matching lines @@
   // variables anymore, because they could lead to optimistic results
   // needing to be re-analyzed.
   checkReturn('returnInt2', typesInferrer.dynamicType);
   checkReturn('returnInt3', typesInferrer.intType);
   checkReturn('returnInt4', typesInferrer.intType);
 
   checkReturn('returnDyn1', typesInferrer.dynamicType);
   checkReturn('returnDyn2', typesInferrer.dynamicType);
   checkReturn('returnDyn3', typesInferrer.dynamicType);
 }