/usr/share/gnome-session/sessions/gnome-flashback.session is in gnome-session-flashback 1:3.8.0-1ubuntu11.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | [GNOME Session]
Name=GNOME Flashback (Metacity)
RequiredComponents=gnome-panel;unity-settings-daemon;metacity;nautilus-classic;gnome-flashback-services;
DesktopName=Unity
|