/usr/share/vala-0.20/vapi/gdk-x11-2.0.deps is in valac-0.20-vapi 0.20.1-2ubuntu5.
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 7 | gio-2.0
gdk-2.0
gdk-pixbuf-2.0
cairo
pango
pangocairo
x11
|