Fill the un-encrypted metadata field in password specifics.

components/sync/base/sync_features.cc

+// Copyright 2016 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 "components/sync/base/sync_features.h"
+
+namespace syncer {
+
+// The feature controls the filling of the unencrypted metadata field for the
+// passwords specifics https://crbug.com/638963.
+const base::Feature kFillPasswordMetadata{"PasswordMetadataFilling",
+                                          base::FEATURE_DISABLED_BY_DEFAULT};
+
+}  // namespace syncer