/usr/include/libinfgtk3-0.6/libinfgtk/ is in libinfinity-0.6-dev 0.6.7-1build1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-account-creation-dialog.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-acl-sheet-view.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-browser-model-filter.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-browser-model-sort.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-browser-model.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-browser-store.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-browser-view.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-certificate-dialog.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-certificate-manager.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-certificate-view.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-chat.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-io.h
/usr/include/libinfgtk3-0.6/libinfgtk/inf-gtk-permissions-dialog.h