/usr/share/php/PEAR/Installer/ is in php-pear 5.3.10-1ubuntu3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/PEAR/Installer/Role/
/usr/share/php/PEAR/Installer/Role.php
/usr/share/php/PEAR/Installer/Role/Cfg.php
/usr/share/php/PEAR/Installer/Role/Cfg.xml
/usr/share/php/PEAR/Installer/Role/Common.php
/usr/share/php/PEAR/Installer/Role/Data.php
/usr/share/php/PEAR/Installer/Role/Data.xml
/usr/share/php/PEAR/Installer/Role/Doc.php
/usr/share/php/PEAR/Installer/Role/Doc.xml
/usr/share/php/PEAR/Installer/Role/Ext.php
/usr/share/php/PEAR/Installer/Role/Ext.xml
/usr/share/php/PEAR/Installer/Role/Php.php
/usr/share/php/PEAR/Installer/Role/Php.xml
/usr/share/php/PEAR/Installer/Role/Script.php
/usr/share/php/PEAR/Installer/Role/Script.xml
/usr/share/php/PEAR/Installer/Role/Src.php
/usr/share/php/PEAR/Installer/Role/Src.xml
/usr/share/php/PEAR/Installer/Role/Test.php
/usr/share/php/PEAR/Installer/Role/Test.xml
/usr/share/php/PEAR/Installer/Role/Www.php
/usr/share/php/PEAR/Installer/Role/Www.xml