/usr/include/libreoffice/osl/ is in libreoffice-dev 1:5.1.2-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libreoffice/osl/conditn.h
/usr/include/libreoffice/osl/conditn.hxx
/usr/include/libreoffice/osl/diagnose.h
/usr/include/libreoffice/osl/doublecheckedlocking.h
/usr/include/libreoffice/osl/endian.h
/usr/include/libreoffice/osl/file.h
/usr/include/libreoffice/osl/file.hxx
/usr/include/libreoffice/osl/getglobalmutex.hxx
/usr/include/libreoffice/osl/interlck.h
/usr/include/libreoffice/osl/module.h
/usr/include/libreoffice/osl/module.hxx
/usr/include/libreoffice/osl/mutex.h
/usr/include/libreoffice/osl/mutex.hxx
/usr/include/libreoffice/osl/nlsupport.h
/usr/include/libreoffice/osl/pipe.h
/usr/include/libreoffice/osl/pipe.hxx
/usr/include/libreoffice/osl/pipe_decl.hxx
/usr/include/libreoffice/osl/process.h
/usr/include/libreoffice/osl/profile.h
/usr/include/libreoffice/osl/profile.hxx
/usr/include/libreoffice/osl/security.h
/usr/include/libreoffice/osl/security.hxx
/usr/include/libreoffice/osl/security_decl.hxx
/usr/include/libreoffice/osl/signal.h
/usr/include/libreoffice/osl/socket.h
/usr/include/libreoffice/osl/socket.hxx
/usr/include/libreoffice/osl/socket_decl.hxx
/usr/include/libreoffice/osl/thread.h
/usr/include/libreoffice/osl/thread.hxx
/usr/include/libreoffice/osl/time.h