Wire sync shutdown reason from PSS all the way down to sync manager.

sync/internal_api/sync_rollback_manager_base.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 SYNC_INTERNAL_API_SYNC_ROLLBACK_MANAGER_BASE_H_
 #define SYNC_INTERNAL_API_SYNC_ROLLBACK_MANAGER_BASE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 41 matching lines @@
       const base::Closure& ready_task,
       const base::Closure& retry_task) OVERRIDE;
   virtual void SetInvalidatorEnabled(bool invalidator_enabled) OVERRIDE;
   virtual void OnIncomingInvalidation(
       syncer::ModelType type,
       scoped_ptr<InvalidationInterface> invalidation) OVERRIDE;
   virtual void AddObserver(SyncManager::Observer* observer) OVERRIDE;
   virtual void RemoveObserver(SyncManager::Observer* observer) OVERRIDE;
   virtual SyncStatus GetDetailedStatus() const OVERRIDE;
   virtual void SaveChanges() OVERRIDE;
-  virtual void ShutdownOnSyncThread() OVERRIDE;
+  virtual void ShutdownOnSyncThread(ShutdownReason reason) OVERRIDE;
   virtual UserShare* GetUserShare() OVERRIDE;
   virtual const std::string cache_guid() OVERRIDE;
   virtual bool ReceivedExperiment(Experiments* experiments) OVERRIDE;
   virtual bool HasUnsyncedItems() OVERRIDE;
   virtual SyncEncryptionHandler* GetEncryptionHandler() OVERRIDE;
   virtual void RefreshTypes(ModelTypeSet types) OVERRIDE;
   virtual SyncContextProxy* GetSyncContextProxy() OVERRIDE;
   virtual ScopedVector<ProtocolEvent> GetBufferedProtocolEvents()
       OVERRIDE;
   virtual scoped_ptr<base::ListValue> GetAllNodesForType(
@@ skipping 63 matching lines @@
   scoped_ptr<SyncEncryptionHandler> dummy_handler_;
 
   bool initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncRollbackManagerBase);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_SYNC_ROLLBACK_MANAGER_BASE_H_