/usr/ is in liblightdm-qt5-3-dev 1.18.3-0ubuntu1.1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/liblightdm-qt5-3.pc
/usr/include/
/usr/include/lightdm-qt5-3/
/usr/include/lightdm-qt5-3/QLightDM/
/usr/include/lightdm-qt5-3/QLightDM/power.h
/usr/include/lightdm-qt5-3/QLightDM/Greeter
/usr/include/lightdm-qt5-3/QLightDM/SessionsModel
/usr/include/lightdm-qt5-3/QLightDM/UsersModel
/usr/include/lightdm-qt5-3/QLightDM/Power
/usr/include/lightdm-qt5-3/QLightDM/greeter.h
/usr/include/lightdm-qt5-3/QLightDM/usersmodel.h
/usr/include/lightdm-qt5-3/QLightDM/sessionsmodel.h
/usr/share/
/usr/share/doc/
/usr/share/doc/liblightdm-qt5-3-dev/
/usr/share/doc/liblightdm-qt5-3-dev/copyright
/usr/lib/x86_64-linux-gnu/liblightdm-qt5-3.so
/usr/share/doc/liblightdm-qt5-3-dev/changelog.Debian.gz