[shill] Profiles need to own their own storage

We're moving to a model where we rely on the StoreInterface
implementation to maintain profile state, instead of managing
a list of Service objects manually.  Thus, we need to allow
Profile to own its own StoreInterface.

BUG=chromium-os:17253
TEST=unit

Change-Id: Ie62462686ecf598efeac08a2d3180cd372430bb9
Reviewed-on: http://gerrit.chromium.org/gerrit/9916
Commit-Ready: Chris Masone <cmasone@chromium.org>
Reviewed-by: Chris Masone <cmasone@chromium.org>
Tested-by: Chris Masone <cmasone@chromium.org>
Reviewed-by: Paul Stewart <pstew@chromium.org>
diff --git a/default_profile.h b/default_profile.h
index d362f48..5dee60a 100644
--- a/default_profile.h
+++ b/default_profile.h
@@ -33,7 +33,7 @@
   // Persists profile information, as well as that of discovered devices
   // and bound services, to disk.
   // Returns true on success, false on failure.
-  virtual bool Save(StoreInterface *storage);
+  virtual bool Save();
 
   // Sets |path| to the persistent store file path for the default, global
   // profile. Returns true on success, and false if unable to determine an