/usr/share/glib-2.0/schemas/org.compiz.imgpng.gschema.xml is in compiz-gnome 1:0.9.13.1+18.04.20180302-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | <?xml version="1.0"?>
<schemalist/>
|