shill: Cellular device obtains Modem status through its Simple interface.

BUG=chromium-os:18315
TEST=unit tests, tested on device

Change-Id: I0eae20e65724387c1acad05acdf85bc6cd20d71f
Reviewed-on: http://gerrit.chromium.org/gerrit/4968
Reviewed-by: Darin Petkov <petkov@chromium.org>
Tested-by: Darin Petkov <petkov@chromium.org>
diff --git a/proxy_factory.h b/proxy_factory.h
index 804dc77..908b699 100644
--- a/proxy_factory.h
+++ b/proxy_factory.h
@@ -21,6 +21,7 @@
 class ModemManager;
 class ModemManagerProxyInterface;
 class ModemProxyInterface;
+class ModemSimpleProxyInterface;
 class SupplicantInterfaceProxyInterface;
 class SupplicantProcessProxyInterface;
 
@@ -45,6 +46,10 @@
   virtual ModemProxyInterface *CreateModemProxy(const std::string &path,
                                                 const std::string &service);
 
+  virtual ModemSimpleProxyInterface *CreateModemSimpleProxy(
+      const std::string &path,
+      const std::string &service);
+
   virtual SupplicantProcessProxyInterface *CreateSupplicantProcessProxy(
       const char *dbus_path,
       const char *dbus_addr);