Addresses a ClassCastException seen in the editor from MemberBuilder

tests/language/src/DefaultFactoryLibrary.dart

Index: tests/language/src/DefaultFactoryLibrary.dart
diff --git a/tests/language/src/DefaultFactoryLibrary.dart b/tests/language/src/DefaultFactoryLibrary.dart
new file mode 100644
index 0000000000000000000000000000000000000000..f6f0ccfb125655d9e6b87e5bd690c2b8586f4dfe
--- /dev/null
+++ b/tests/language/src/DefaultFactoryLibrary.dart
@@ -0,0 +1,14 @@
+// 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.
+
+// Dart test program for testing default factories defined across libraries
+
+#library("lib");
+#import("DefaultFactoryLibraryTest.dart", prefix:"test");
+
+// References a factory class in another library
+interface A factory test.C {
+  A();
+  int methodA();
+}