/usr/share/php/ is in php-horde-autoloader 2.1.2-1ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/Horde/
/usr/share/php/Horde/Autoloader.php
/usr/share/php/Horde/Autoloader/
/usr/share/php/Horde/Autoloader/Default.php
/usr/share/php/Horde/Autoloader/ClassPathMapper.php
/usr/share/php/Horde/Autoloader/ClassPathMapper/
/usr/share/php/Horde/Autoloader/ClassPathMapper/Default.php
/usr/share/php/Horde/Autoloader/ClassPathMapper/Prefix.php
/usr/share/php/Horde/Autoloader/ClassPathMapper/PrefixString.php
/usr/share/php/Horde/Autoloader/ClassPathMapper/Application.php
/usr/share/php/.registry/
/usr/share/php/.registry/.channel.pear.horde.org/
/usr/share/php/.registry/.channel.pear.horde.org/horde_autoloader.reg