shill: vpn: Don't mark VPN services as auto-connect automatically.

BUG=chromium-os:30246
TEST=050IPSecGenesis

Change-Id: I8927e69d5cab614364f8d803a1255e458fb33015
Reviewed-on: https://gerrit.chromium.org/gerrit/21461
Tested-by: Darin Petkov <petkov@chromium.org>
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Commit-Ready: Darin Petkov <petkov@chromium.org>
diff --git a/vpn_service.h b/vpn_service.h
index a1e5193..b7b456a 100644
--- a/vpn_service.h
+++ b/vpn_service.h
@@ -32,6 +32,7 @@
   virtual bool Load(StoreInterface *storage);
   virtual bool Save(StoreInterface *storage);
   virtual bool Unload();
+  virtual void MakeFavorite();
 
   virtual void InitDriverPropertyStore();