Let SyncBackupManager keep backup data in memory until shutdown. Only persist

sync/internal_api/internal_components_factory_impl.cc

 // 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.
 
 #include "sync/internal_api/public/internal_components_factory_impl.h"
 
 #include "sync/engine/backoff_delay_provider.h"
 #include "sync/engine/syncer.h"
 #include "sync/engine/sync_scheduler_impl.h"
 #include "sync/sessions/sync_session_context.h"
+#include "sync/syncable/deferred_on_disk_directory_backing_store.h"
 #include "sync/syncable/on_disk_directory_backing_store.h"
 
 using base::TimeDelta;
 
 namespace syncer {
 
 InternalComponentsFactoryImpl::InternalComponentsFactoryImpl(
     const Switches& switches) : switches_(switches) {
 }
 
@@ skipping 31 matching lines @@
           listeners, debug_info_getter,
           model_type_registry,
           switches_.encryption_method == ENCRYPTION_KEYSTORE,
           switches_.pre_commit_updates_policy ==
               FORCE_ENABLE_PRE_COMMIT_UPDATE_AVOIDANCE,
           invalidation_client_id));
 }
 
 scoped_ptr<syncable::DirectoryBackingStore>
 InternalComponentsFactoryImpl::BuildDirectoryBackingStore(
-      const std::string& dir_name, const base::FilePath& backing_filepath) {
-  return scoped_ptr<syncable::DirectoryBackingStore>(
-      new syncable::OnDiskDirectoryBackingStore(dir_name, backing_filepath));
+    StorageOption storage, const std::string& dir_name,
+    const base::FilePath& backing_filepath) {
+  if (storage == STORAGE_ON_DISK) {
+    return scoped_ptr<syncable::DirectoryBackingStore>(
+        new syncable::OnDiskDirectoryBackingStore(dir_name, backing_filepath));
+  } else if (storage == STORAGE_ON_DISK_DEFERRED) {
+    return scoped_ptr<syncable::DirectoryBackingStore>(
+        new syncable::DeferredOnDiskDirectoryBackingStore(dir_name,
+                                                          backing_filepath));
+  } else {
+    NOTREACHED();
+    return scoped_ptr<syncable::DirectoryBackingStore>();
+  }
 }
 
 InternalComponentsFactory::Switches
 InternalComponentsFactoryImpl::GetSwitches() const {
   return switches_;
 }
 
 }  // namespace syncer