/usr/share/themes/Metabox/xfwm4/themerc is in xfwm4-themes 4.10.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | full_width_title=true
button_spacing=0
button_offset=1
button_layout=O|HMC
title_vertical_offset_active=0
title_vertical_offset_inactive=0
|