/usr/ is in gnome-session-canberra 0.28-3ubuntu3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/gnome/
/usr/share/gnome/autostart/
/usr/share/
/usr/share/doc/
/usr/share/doc/gnome-session-canberra/
/usr/share/doc/gnome-session-canberra/copyright
/usr/share/man/
/usr/share/man/man1/
/usr/share/man/man1/canberra-gtk-play.1.gz
/usr/share/gnome/autostart/libcanberra-login-sound.desktop
/usr/share/gnome/shutdown/
/usr/share/gnome/shutdown/libcanberra-logout-sound.sh
/usr/share/gdm/
/usr/share/gdm/autostart/
/usr/share/gdm/autostart/LoginWindow/
/usr/share/gdm/autostart/LoginWindow/libcanberra-ready-sound.desktop
/usr/share/glib-2.0/
/usr/share/glib-2.0/schemas/
/usr/share/glib-2.0/schemas/10_gnome-session-canberra.gschema.override
/usr/bin/
/usr/bin/canberra-gtk-play
/usr/share/doc/gnome-session-canberra/README.gz
/usr/share/doc/gnome-session-canberra/changelog.Debian.gz