Migrate block 162 to Dart 2.0.

tests/language_2/type_variable_closure2_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";
 
 class A<T> {}
 
 class C<T> {
   a() {
@@ skipping 11 matching lines @@
 
 main() {
   Expect.isTrue(new C<int>().a()() is A<int>);
   Expect.isFalse(new C<int>().a()() is A<String>);
   Expect.isTrue(new C<int>().list()() is List<int>);
   Expect.isFalse(new C<int>().list()() is List<String>);
   Expect.isTrue(new C<int>().map()() is Map<int, int>);
   Expect.isFalse(new C<int>().map()() is Map<String, int>);
   Expect.isFalse(new C<int>().map()() is Map<int, String>);
 }