/usr/share/php/Horde/ is in php-horde-service-twitter 2.1.1-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/Horde/Service/
/usr/share/php/Horde/Service/Twitter/
/usr/share/php/Horde/Service/Twitter.php
/usr/share/php/Horde/Service/Twitter/Account.php
/usr/share/php/Horde/Service/Twitter/Auth/
/usr/share/php/Horde/Service/Twitter/Auth.php
/usr/share/php/Horde/Service/Twitter/Auth/Oauth.php
/usr/share/php/Horde/Service/Twitter/Exception.php
/usr/share/php/Horde/Service/Twitter/Favorites.php
/usr/share/php/Horde/Service/Twitter/Request/
/usr/share/php/Horde/Service/Twitter/Request.php
/usr/share/php/Horde/Service/Twitter/Request/Oauth.php
/usr/share/php/Horde/Service/Twitter/Statuses.php