SyncFS: Factor out DriveMetadataDB migration functions

chrome/browser/sync_file_system/drive/metadata_db_migration_util.h

Index: chrome/browser/sync_file_system/drive/metadata_db_migration_util.h
diff --git a/chrome/browser/sync_file_system/drive/metadata_db_migration_util.h b/chrome/browser/sync_file_system/drive/metadata_db_migration_util.h
index 2a851c5810b457184d3948b98c7d2ccfb0c5c6ba..bf8f7c87ecd47da9c4bf5641bf7b0a9a07ab47a3 100644
--- a/chrome/browser/sync_file_system/drive/metadata_db_migration_util.h
+++ b/chrome/browser/sync_file_system/drive/metadata_db_migration_util.h
@@ -33,6 +33,9 @@ std::string AddWapiIdPrefix(const std::string& resource_id,
 //   "zzz"         =>  "zzz"
 std::string RemoveWapiIdPrefix(const std::string& resource_id);
 
+// Migrate |db| scheme from version 0 to version 1.
+SyncStatusCode MigrateDatabaseFromV0ToV1(leveldb::DB* db);
+
 // Migrate |db| scheme from version 1 to version 2.
 SyncStatusCode MigrateDatabaseFromV1ToV2(leveldb::DB* db);