Fill the un-encrypted metadata field in password specifics.

components/sync/core/base_transaction.cc

Index: components/sync/core/base_transaction.cc
diff --git a/components/sync/core/base_transaction.cc b/components/sync/core/base_transaction.cc
index ca61433b5c0ac49182e81559c2404d949f59b7f7..fb67693f19d2323fc5fb7b0da74f95906969e417 100644
--- a/components/sync/core/base_transaction.cc
+++ b/components/sync/core/base_transaction.cc
@@ -29,4 +29,11 @@ ModelTypeSet BaseTransaction::GetEncryptedTypes() const {
              : ModelTypeSet();
 }
 
+PassphraseType BaseTransaction::GetPassphraseType() const {
+  syncable::NigoriHandler* nigori_handler = GetDirectory()->GetNigoriHandler();
+  return nigori_handler
+             ? nigori_handler->GetPassphraseType(this->GetWrappedTrans())
+             : PassphraseType::IMPLICIT_PASSPHRASE;
+}
+
 }  // namespace syncer