/usr/share/php/ is in php-mdb2-driver-mysql 1.5.0b4-1ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/MDB2/Driver/Reverse/
/usr/share/php/data/
/usr/share/php/data/MDB2_Driver_mysql/
/usr/share/php/data/MDB2_Driver_mysql/package_mysql.xml
/usr/share/php/MDB2/
/usr/share/php/MDB2/Driver/
/usr/share/php/MDB2/Driver/Reverse/mysql.php
/usr/share/php/MDB2/Driver/mysql.php
/usr/share/php/MDB2/Driver/Datatype/
/usr/share/php/MDB2/Driver/Datatype/mysql.php
/usr/share/php/MDB2/Driver/Native/
/usr/share/php/MDB2/Driver/Native/mysql.php
/usr/share/php/MDB2/Driver/Manager/
/usr/share/php/MDB2/Driver/Manager/mysql.php
/usr/share/php/MDB2/Driver/Function/
/usr/share/php/MDB2/Driver/Function/mysql.php
/usr/share/php/.registry/
/usr/share/php/.registry/mdb2_driver_mysql.reg