/usr/share/ is in gnome-session 3.2.1-0ubuntu8.
This file is owned by root:root, with mode 0o755.
..
/usr/share/doc/
/usr/share/doc/gnome-session/
/usr/share/doc/gnome-session/README.Debian
/usr/share/doc/gnome-session/copyright
/usr/share/doc/gnome-session/dbus/
/usr/share/doc/gnome-session/dbus/gnome-session.html
/usr/share/xsessions/
/usr/share/xsessions/gnome.desktop
/usr/share/xsessions/gnome-shell.desktop
/usr/share/xsessions/ubuntu.desktop
/usr/share/xsessions/ubuntu-2d.desktop
/usr/share/gnome-session/
/usr/share/gnome-session/sessions/
/usr/share/gnome-session/sessions/gnome.session
/usr/share/gnome-session/sessions/ubuntu.session
/usr/share/gnome-session/sessions/ubuntu-2d.session
/usr/share/doc/gnome-session/README
/usr/share/doc/gnome-session/AUTHORS
/usr/share/doc/gnome-session/NEWS.gz
/usr/share/doc/gnome-session/changelog.Debian.gz