/usr/share/ is in gnome-shell-mailnag 3.26.0-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/doc/
/usr/share/doc/gnome-shell-mailnag/
/usr/share/doc/gnome-shell-mailnag/README.md
/usr/share/doc/gnome-shell-mailnag/changelog.Debian.gz
/usr/share/doc/gnome-shell-mailnag/copyright
/usr/share/glib-2.0/
/usr/share/glib-2.0/schemas/
/usr/share/glib-2.0/schemas/org.gnome.shell.extensions.mailnag.gschema.xml
/usr/share/gnome-shell/
/usr/share/gnome-shell/extensions/
/usr/share/gnome-shell/extensions/mailnag@pulb.github.com/
/usr/share/gnome-shell/extensions/mailnag@pulb.github.com/convenience.js
/usr/share/gnome-shell/extensions/mailnag@pulb.github.com/extension.js
/usr/share/gnome-shell/extensions/mailnag@pulb.github.com/indicator.js
/usr/share/gnome-shell/extensions/mailnag@pulb.github.com/metadata.json
/usr/share/gnome-shell/extensions/mailnag@pulb.github.com/opts.js
/usr/share/gnome-shell/extensions/mailnag@pulb.github.com/prefs.js
/usr/share/gnome-shell/extensions/mailnag@pulb.github.com/stylesheet.css
/usr/share/gnome-shell/extensions/mailnag@pulb.github.com/utils.js