Checked mode test fix.

tests/lib/unittest/unittest_test.dart

 // Copyright (c) 2012, 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.
 
 // TODO(gram):
 // Unfortunately I can't seem to test anything that involves timeouts, e.g.
 // insufficient callbacks, because the timeout is controlled externally
 // (test.dart?), and we would need to use a shorter timeout for the inner tests
 // so the outer timeout doesn't fire. So I removed all such tests.
 // I'd like to revisit this at some point.
@@ skipping 62 matching lines @@
 }
 
 class MockList extends Mock implements List {
 }
 
 class Foo {
   sum(a, b, c) => a + b + c;
 }
 
 class FooSpy extends Mock implements Foo {
-  FooSpy real;
+  Foo real;
   FooSpy() {
     real = new Foo();
     this.when(callsTo('sum')).alwaysCall(real.sum);
   }
 }
 
 runTest() {
   port.receive((testName, sendport) {
     configure(_testconfig = new TestConfiguration(sendport));
     if (testName == 'single correct test') {
@@ skipping 177 matching lines @@
         message: 'Caught Exception: No behavior specified for method foo'),
     buildStatusString(0, 1, 0, tests[15],
         message: 'Expected sum() to sometimes return <0> but: never did')
   ];
 
   actual = [];
 
   nextTest(0);
 }