/usr/share/gdm/autostart/LoginWindow/mythbuntu-gdm-window-manager.desktop is in mythbuntu-gdm-theme 0.6-0ubuntu1.
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 | [Desktop Entry]
Type=Application
Encoding=UTF-8
Name=Xfwm4
Exec=xfwm4
|