Implement ClosureMirror.

dart/tests/lib/mirrors/mirrors_test.dart

Index: dart/tests/lib/mirrors/mirrors_test.dart
diff --git a/dart/tests/lib/mirrors/mirrors_test.dart b/dart/tests/lib/mirrors/mirrors_test.dart
index 7509467f4a36513c8585bb66d8f1b415af9c3a7b..df634b20fa578b8b4968b20f3be3f296cd4fb4ff 100644
--- a/dart/tests/lib/mirrors/mirrors_test.dart
+++ b/dart/tests/lib/mirrors/mirrors_test.dart
@@ -204,8 +204,8 @@ mainWithArgument({bool isDart2js}) {
   test("Test instance field access", () { testInstanceFieldAccess(mirrors); });
   test('Test intercepted objects', () { testIntercepted(mirrors); });
   test("Test field access", () { testFieldAccess(mirrors); });
-  if (isDart2js) return;
   test("Test closure mirrors", () { testClosureMirrors(mirrors); });
+  if (isDart2js) return;
   test("Test invoke constructor", () { testInvokeConstructor(mirrors); });
   test("Test reflect type", () { testReflectClass(mirrors); });
   test("Test simple and qualifiedName", () { testNames(mirrors); });