Introduce a layering in the invalidation component as public and impl

components/invalidation/impl/invalidator_storage.h

 // 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.
 
-#ifndef COMPONENTS_INVALIDATION_INVALIDATOR_STORAGE_H_
-#define COMPONENTS_INVALIDATION_INVALIDATOR_STORAGE_H_
+#ifndef COMPONENTS_INVALIDATION_IMPL_INVALIDATOR_STORAGE_H_
+#define COMPONENTS_INVALIDATION_IMPL_INVALIDATOR_STORAGE_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/threading/thread_checker.h"
-#include "components/invalidation/invalidation_state_tracker.h"
+#include "components/invalidation/impl/invalidation_state_tracker.h"
 
 class PrefRegistrySimple;
 class PrefService;
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 namespace invalidation {
 
@@ skipping 27 matching lines @@
  private:
   base::ThreadChecker thread_checker_;
 
   PrefService* const pref_service_;
 
   DISALLOW_COPY_AND_ASSIGN(InvalidatorStorage);
 };
 
 }  // namespace invalidation
 
-#endif  // COMPONENTS_INVALIDATION_INVALIDATOR_STORAGE_H_
+#endif  // COMPONENTS_INVALIDATION_IMPL_INVALIDATOR_STORAGE_H_