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

sdk/lib/_internal/compiler/implementation/scanner/listener.dart

Index: sdk/lib/_internal/compiler/implementation/scanner/listener.dart
diff --git a/sdk/lib/_internal/compiler/implementation/scanner/listener.dart b/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
index 4d4ad081ce433ca8629f140cc43ef882013e8d61..28acaefa32366a3c8344e405f62832203667afce 100644
--- a/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
+++ b/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
@@ -918,7 +918,7 @@ class ElementListener extends Listener {
     int id = idGenerator();
     PartialClassElement element = new PartialClassElement(
         name.source, beginToken, endToken, compilationUnitElement, id);
-    element.nativeTagInfo = nativeTagInfo;
+    element.setNative(nativeTagInfo);
     pushElement(element);
     rejectBuiltInIdentifier(name);
   }