Revert of Move some sync/notifier to components/invalidation

sync/notifier/invalidation_state_tracker.cc

Index: sync/notifier/invalidation_state_tracker.cc
diff --git a/sync/notifier/invalidation_state_tracker.cc b/sync/notifier/invalidation_state_tracker.cc
deleted file mode 100644
index ab3ce176649c524f5ebc868f4451832e9b4b6e35..0000000000000000000000000000000000000000
--- a/sync/notifier/invalidation_state_tracker.cc
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2014 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/invalidation_state_tracker.h"
-
-namespace syncer {
-
-InvalidationStateTracker::InvalidationStateTracker() {}
-
-InvalidationStateTracker::~InvalidationStateTracker() {}
-
-}  // namespace syncer