/usr/share/php/Symfony/Component/Security/Acl/Domain/ is in php-symfony-security 2.7.10-0ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/Symfony/Component/Security/Acl/Domain/Acl.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/AclCollectionCache.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/AuditLogger.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/DoctrineAclCache.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/Entry.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/FieldEntry.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/ObjectIdentity.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/ObjectIdentityRetrievalStrategy.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/PermissionGrantingStrategy.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/RoleSecurityIdentity.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/SecurityIdentityRetrievalStrategy.php
/usr/share/php/Symfony/Component/Security/Acl/Domain/UserSecurityIdentity.php