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

sync/notifier/sync_notifier_factory.h

 // 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.
 
 #ifndef SYNC_NOTIFIER_SYNC_NOTIFIER_FACTORY_H_
 #define SYNC_NOTIFIER_SYNC_NOTIFIER_FACTORY_H_
 
 #include <string>
 
 #include "base/memory/weak_ptr.h"
@@ skipping 21 matching lines @@
 
   // Creates a sync notifier. Caller takes ownership of the returned
   // object.  However, the returned object must not outlive the
   // factory from which it was created.  Can be called on any thread.
   SyncNotifier* CreateSyncNotifier();
 
  private:
   const notifier::NotifierOptions notifier_options_;
   const std::string client_info_;
   const InvalidationVersionMap initial_max_invalidation_versions_;
+  const std::string initial_invalidation_state_;
   const browser_sync::WeakHandle<InvalidationStateTracker>
       invalidation_state_tracker_;
 };
 
 }  // namespace sync_notifier
 
 #endif  // SYNC_NOTIFIER_SYNC_NOTIFIER_FACTORY_H_