Migrate block 163 to Dart 2.0.

tests/language_2/unbound_getter_test.dart

 // Copyright (c) 2011, 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.
-
-// Test that an unresolved method call in a factory is a resolution
-// error.
+// Verify that an unbound getter is properly resolved at runtime.
 
 class A {
-  factory A() {
-    foo();
+  const A();
+  foo() {
+    return y; /*@compile-error=unspecified*/
   }
 }
 
 main() {
-  new A();
+  new A().foo();
 }