[SyncFS] Implement SyncEngineInitializer

chrome/browser/sync_file_system/drive_backend/metadata_database.cc

 // 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.
 
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.h"
 
 #include <algorithm>
 #include <stack>
 
 #include "base/bind.h"
@@ skipping 547 matching lines @@
   STLDeleteContainerPairSecondPointers(
       file_by_id_.begin(), file_by_id_.end());
   STLDeleteContainerPairSecondPointers(
       tracker_by_id_.begin(), tracker_by_id_.end());
 }
 
 int64 MetadataDatabase::GetLargestChangeID() const {
   return service_metadata_->largest_change_id();
 }
 
+int64 MetadataDatabase::GetSyncRootTrackerID() const {
+  return service_metadata_->sync_root_tracker_id();
+}
+
 bool MetadataDatabase::HasSyncRoot() const {
   return service_metadata_->has_sync_root_tracker_id() &&
       !!service_metadata_->sync_root_tracker_id();
 }
 
 void MetadataDatabase::PopulateInitialData(
     int64 largest_change_id,
     const google_apis::FileResource& sync_root_folder,
     const ScopedVector<google_apis::FileResource>& app_root_folders,
     const SyncStatusCallback& callback) {
@@ skipping 890 matching lines @@
       FROM_HERE,
       base::Bind(&leveldb::DB::Write,
                  base::Unretained(db_.get()),
                  leveldb::WriteOptions(),
                  base::Owned(batch.release())),
       base::Bind(&AdaptLevelDBStatusToSyncStatusCode, callback));
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system