/usr/ is in signon-plugins-dev 8.59+17.10.20170606-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/
/usr/share/doc/
/usr/share/doc/signon-plugins-dev/
/usr/include/
/usr/include/signon-plugins/
/usr/include/signon-plugins/SignOn/
/usr/include/signon-plugins/SignOn/AuthPluginInterface
/usr/include/signon-plugins/SignOn/UiSessionData
/usr/include/signon-plugins/SignOn/authpluginif.h
/usr/include/signon-plugins/SignOn/blobiohandler.h
/usr/include/signon-plugins/SignOn/signonplugincommon.h
/usr/include/signon-plugins/SignOn/uisessiondata.h
/usr/include/signon-plugins/SignOn/uisessiondata_priv.h
/usr/include/signon-plugins/passwordplugin.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/signon-plugins-common.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/signon-plugins.pc
/usr/share/doc/signon-plugins-dev/copyright
/usr/share/doc/signon-plugins-dev/example/
/usr/share/doc/signon-plugins-dev/example/exampledata.h
/usr/share/doc/signon-plugins-dev/example/exampleplugin.cpp.gz
/usr/share/doc/signon-plugins-dev/example/exampleplugin.h
/usr/share/doc/signon-plugins-dev/example/exampleplugin.pro
/usr/lib/x86_64-linux-gnu/libsignon-plugins.so
/usr/share/doc/signon-plugins-dev/changelog.Debian.gz