/usr/include/ is in libpolkit-gobject-1-dev 0.105-14.1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/polkit-1/
/usr/include/polkit-1/polkit/
/usr/include/polkit-1/polkit/polkit.h
/usr/include/polkit-1/polkit/polkitenumtypes.h
/usr/include/polkit-1/polkit/polkitunixuser.h
/usr/include/polkit-1/polkit/polkitimplicitauthorization.h
/usr/include/polkit-1/polkit/polkitsystembusname.h
/usr/include/polkit-1/polkit/polkitunixgroup.h
/usr/include/polkit-1/polkit/polkitidentity.h
/usr/include/polkit-1/polkit/polkittypes.h
/usr/include/polkit-1/polkit/polkitpermission.h
/usr/include/polkit-1/polkit/polkitsubject.h
/usr/include/polkit-1/polkit/polkitauthority.h
/usr/include/polkit-1/polkit/polkitprivate.h
/usr/include/polkit-1/polkit/polkitauthorityfeatures.h
/usr/include/polkit-1/polkit/polkiterror.h
/usr/include/polkit-1/polkit/polkitunixsession.h
/usr/include/polkit-1/polkit/polkittemporaryauthorization.h
/usr/include/polkit-1/polkit/polkitauthorizationresult.h
/usr/include/polkit-1/polkit/polkitactiondescription.h
/usr/include/polkit-1/polkit/polkitunixprocess.h
/usr/include/polkit-1/polkit/polkitunixnetgroup.h
/usr/include/polkit-1/polkit/polkitcheckauthorizationflags.h
/usr/include/polkit-1/polkit/polkitdetails.h