/usr/share/unity-control-center/keybindings/50-compiz-windows.xml is in compiz-gnome 1:0.9.11+14.04.20140409-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/unity-control-center/keybindings/../../gnome-control-center/keybindings/50-compiz-windows.xml