/usr/share/lightning/extensions/langpack-br@lightning.debian.org/chrome.manifest is in lightning-l10n-br 1:52.9.1-1~deb9u1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | locale calendar br jar:chrome/br.jar!/locale/br/calendar/
locale lightning br jar:chrome/br.jar!/locale/br/lightning/
|