Track active references in ShillClientHelper (Take 3)

dbus/object_proxy.h

Index: dbus/object_proxy.h
diff --git a/dbus/object_proxy.h b/dbus/object_proxy.h
index b183be2ccda0287dc9e8ec932b8bdaeaf5f89330..48c9c03208ab93865ce3d30907e8e256eabdb815 100644
--- a/dbus/object_proxy.h
+++ b/dbus/object_proxy.h
@@ -166,6 +166,8 @@ class CHROME_DBUS_EXPORT ObjectProxy
   // BLOCKING CALL.
   virtual void Detach();
 
+  const ObjectPath& object_path() const { return object_path_; }
+
   // Returns an empty callback that does nothing. Can be used for
   // CallMethod().
   static ResponseCallback EmptyResponseCallback();