shill: Basic implementation of Device::Register DBus service method.

BUG=chromium-os:19806
TEST=unit tests

Change-Id: I41052f52dd67b7ef77209f7ddd693ab90f226d78
Reviewed-on: http://gerrit.chromium.org/gerrit/6936
Reviewed-by: Darin Petkov <petkov@chromium.org>
Tested-by: Darin Petkov <petkov@chromium.org>
diff --git a/device.h b/device.h
index 3a7d6f6..b876b48 100644
--- a/device.h
+++ b/device.h
@@ -62,6 +62,9 @@
 
   virtual void ConfigIP() {}
 
+  // The default implementation sets |error| to kNotSupported.
+  virtual void RegisterOnNetwork(const std::string &network_id, Error *error);
+
   std::string GetRpcIdentifier();
   std::string GetStorageIdentifier();