shill: vpn: Implement L2TPIPSecDriver::Connect and GetSec callback.

BUG=chromium-os:26843,chromium-os:29367
TEST=unit tests

Change-Id: I3a04c118da0b4c397b851ff69625461be455d135
Reviewed-on: https://gerrit.chromium.org/gerrit/20679
Reviewed-by: Darin Petkov <petkov@chromium.org>
Tested-by: Darin Petkov <petkov@chromium.org>
Commit-Ready: Darin Petkov <petkov@chromium.org>
diff --git a/rpc_task_dbus_adaptor.h b/rpc_task_dbus_adaptor.h
index 5ab9da8..5096c75 100644
--- a/rpc_task_dbus_adaptor.h
+++ b/rpc_task_dbus_adaptor.h
@@ -34,6 +34,8 @@
   virtual const std::string &GetRpcConnectionIdentifier();
 
   // Implementation of Task_adaptor
+  virtual void getsec(
+      std::string &user, std::string &password, DBus::Error &error);
   virtual void notify(const std::string &reason,
                       const std::map<std::string, std::string> &dict,
                       DBus::Error &error);