Persist Directory to disk when the app is backgrounded.

chrome/browser/sync/glue/sync_backend_host_core.h

 // Copyright 2013 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 CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_CORE_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_CORE_H_
 
 #include "base/memory/ref_counted.h"
 
 #include "base/timer/timer.h"
@@ skipping 195 matching lines @@
       const base::Callback<void(syncer::ModelTypeSet,
                                 syncer::ModelTypeSet)>& ready_task,
       const base::Closure& retry_callback);
   void DoFinishConfigureDataTypes(
       syncer::ModelTypeSet types_to_config,
       const base::Callback<void(syncer::ModelTypeSet,
                                 syncer::ModelTypeSet)>& ready_task);
   void DoRetryConfiguration(
       const base::Closure& retry_callback);
 
+  // Saves the directory to disk.
+  void DoFlushDirectory();
+
   // Set the base request context to use when making HTTP calls.
   // This method will add a reference to the context to persist it
   // on the IO thread. Must be removed from IO thread.
 
   syncer::SyncManager* sync_manager() { return sync_manager_.get(); }
 
   SyncedDeviceTracker* synced_device_tracker() {
     return synced_device_tracker_.get();
   }
 
@@ skipping 102 matching lines @@
   std::string signin_scoped_device_id_;
 
   base::WeakPtrFactory<SyncBackendHostCore> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncBackendHostCore);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_CORE_H_