sync: migrate invalidation state from syncable::Directory to InvalidationStorage

sync/notifier/mock_invalidation_state_tracker.cc

Index: sync/notifier/mock_invalidation_state_tracker.cc
diff --git a/sync/notifier/mock_invalidation_state_tracker.cc b/sync/notifier/mock_invalidation_state_tracker.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bf55011143c8c1c199f5b4a87fc2f3de6a20971c
--- /dev/null
+++ b/sync/notifier/mock_invalidation_state_tracker.cc
@@ -0,0 +1,12 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "sync/notifier/mock_invalidation_state_tracker.h"
+
+namespace sync_notifier {
+
+MockInvalidationStateTracker::MockInvalidationStateTracker() {}
+MockInvalidationStateTracker::~MockInvalidationStateTracker() {}
+
+}  // namespace sync_notifier