/usr/ is in php-horde-service-gravatar 1.0.1-1ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/
/usr/share/php/
/usr/share/php/Horde/
/usr/share/php/Horde/Service/
/usr/share/php/Horde/Service/Gravatar.php
/usr/share/php/.registry/
/usr/share/php/.registry/.channel.pear.horde.org/
/usr/share/php/.registry/.channel.pear.horde.org/horde_service_gravatar.reg
/usr/share/doc/
/usr/share/doc/php-horde-service-gravatar/
/usr/share/doc/php-horde-service-gravatar/examples/
/usr/share/doc/php-horde-service-gravatar/examples/fetch_profile.php
/usr/share/doc/php-horde-service-gravatar/examples/fetch_avatar.php
/usr/share/doc/php-horde-service-gravatar/examples/get_profile.php
/usr/share/doc/php-horde-service-gravatar/copyright
/usr/share/doc/php-horde-service-gravatar/changelog.Debian.gz
/usr/share/doc/php-horde-service-gravatar/package.xml.gz