/etc/aptdaemon/high-trust-repository-whitelist.d/aptdaemon-trust-webapps.cfg is in unity-webapps-common 2.4.17+15.10.20150616-0ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | [webapps]
origin = Ubuntu
component = universe
pkgnames = unity-webapps-.*
|