shill: Add an org.freedesktop.DBus service proxy.

The proxy will be used in a subsequent CL to listen to RPC services appearing
and disappearing.

BUG=chromium-os:31712
TEST=unit tests

Change-Id: I6cca8da09db43cf03c037a6e1063f129afe49dd3
Reviewed-on: https://gerrit.chromium.org/gerrit/25545
Reviewed-by: Ben Chan <benchan@chromium.org>
Commit-Ready: Darin Petkov <petkov@chromium.org>
Tested-by: Darin Petkov <petkov@chromium.org>
diff --git a/proxy_factory.cc b/proxy_factory.cc
index 0d4566c..a4f2adc 100644
--- a/proxy_factory.cc
+++ b/proxy_factory.cc
@@ -8,6 +8,7 @@
 
 #include "shill/dbus_objectmanager_proxy.h"
 #include "shill/dbus_properties_proxy.h"
+#include "shill/dbus_service_proxy.h"
 #include "shill/dhcpcd_proxy.h"
 #include "shill/mm1_modem_modem3gpp_proxy.h"
 #include "shill/mm1_modem_modemcdma_proxy.h"
@@ -62,6 +63,10 @@
   return new DBusPropertiesProxy(connection(), path, service);
 }
 
+DBusServiceProxyInterface *ProxyFactory::CreateDBusServiceProxy() {
+  return new DBusServiceProxy(connection());
+}
+
 ModemManagerProxyInterface *ProxyFactory::CreateModemManagerProxy(
     ModemManagerClassic *manager,
     const string &path,