Add @Native(...) annotation for native class names.

tests/compiler/dart2js_native/native_class_inheritance2_frog_test.dart

Index: tests/compiler/dart2js_native/native_class_inheritance2_frog_test.dart
diff --git a/tests/compiler/dart2js_native/native_class_inheritance2_frog_test.dart b/tests/compiler/dart2js_native/native_class_inheritance2_frog_test.dart
index 7177573baa247af0dd8028bda6c33c48d6dd2146..bb5d7fb2c873acda5194e27680fbb5696c6c6a49 100644
--- a/tests/compiler/dart2js_native/native_class_inheritance2_frog_test.dart
+++ b/tests/compiler/dart2js_native/native_class_inheritance2_frog_test.dart
@@ -2,6 +2,7 @@
 // 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 "dart:_js_helper";
 import "package:expect/expect.dart";
 
 // Test to see if resolving a hidden native class's method interferes with
@@ -9,18 +10,22 @@ import "package:expect/expect.dart";
 // superclass caches the method in the prototype, so shadowing the dispatcher
 // stored on Object.prototype.
 
-class A native "A" {
+@Native("A")
+class A {
   foo([a=100]) native;
 }
 
-class B extends A native "B" {
+@Native("B")
+class B extends A {
 }
 
-class C extends B native "C" {
+@Native("C")
+class C extends B {
   foo([z=300]) native;
 }
 
-class D extends C native "D" {
+@Native("D")
+class D extends C {
 }
 
 makeA() native;