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

tests/compiler/dart2js_native/native_method_inlining_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 native methods with unnamed optional arguments are called with the
 // number of arguments in the call site AND the call site is inlined.
 
 import "package:expect/expect.dart";
-import 'dart:_js_helper' show NoInline;
+import 'dart:_js_helper' show Native, NoInline;
 
 typedef int Int2Int(int x);
 
-class A native "A" {
+@Native("A")
+class A {
   int foo([x, y, z]) native;
 
   // Calls can be inlined provided they don't pass an argument.
   int callFun([Int2Int fn]) native;
 }
 
 class B {
   static var g;
   @NoInline()
   method1(a) {
@@ skipping 119 matching lines @@
   var b = new B();
   Expect.equals(2, b.method2());
   Expect.equals(246, b.method3());
 }
 
 main() {
   setup();
   test1();
   test2();
 }