[shill] Add code for persisting profiles and services to disk.

BUG=chromium-os:17253
TEST=unit

Change-Id: Ic6dbbcb10543da3f4615cb305a77f6b9b301e8bc
Reviewed-on: http://gerrit.chromium.org/gerrit/7633
Reviewed-by: Darin Petkov <petkov@chromium.org>
Tested-by: Chris Masone <cmasone@chromium.org>
diff --git a/ethernet_service.h b/ethernet_service.h
index 88aa8b5..2934c6a 100644
--- a/ethernet_service.h
+++ b/ethernet_service.h
@@ -30,7 +30,7 @@
   virtual void Disconnect();
 
   // ethernet_<MAC>
-  virtual std::string GetStorageIdentifier(const std::string &mac);
+  virtual std::string GetStorageIdentifier();
 
  private:
   static const char kServiceType[];