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.cc b/rpc_task_dbus_adaptor.cc
index 4f9f67c..ed4ead4 100644
--- a/rpc_task_dbus_adaptor.cc
+++ b/rpc_task_dbus_adaptor.cc
@@ -42,6 +42,11 @@
   return connection_name_;
 }
 
+void RPCTaskDBusAdaptor::getsec(
+    string &user, string &password, DBus::Error &error) {
+  task_->GetLogin(&user, &password);
+}
+
 void RPCTaskDBusAdaptor::notify(const string &reason,
                                 const map<string, string> &dict,
                                 DBus::Error &/*error*/) {