shill: storage: Load and store uint64 values

BUG=chromium-os:31584
TEST=New unit tests; list-devices on a real machine

Change-Id: I48e58ad50e7ce15620d282d7a867b1ab253a2f56
Reviewed-on: https://gerrit.chromium.org/gerrit/27246
Reviewed-by: Ben Chan <benchan@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
Commit-Ready: Paul Stewart <pstew@chromium.org>
diff --git a/mock_store.h b/mock_store.h
index 86dd4f9..73aece7 100644
--- a/mock_store.h
+++ b/mock_store.h
@@ -48,6 +48,12 @@
   MOCK_METHOD3(SetInt, bool(const std::string &group,
                             const std::string &key,
                             int value));
+  MOCK_CONST_METHOD3(GetUint64, bool(const std::string &group,
+                                     const std::string &key,
+                                     uint64 *value));
+  MOCK_METHOD3(SetUint64, bool(const std::string &group,
+                               const std::string &key,
+                               uint64 value));
   MOCK_CONST_METHOD3(GetStringList, bool(const std::string &group,
                                          const std::string &key,
                                          std::vector<std::string> *value));