/usr/share/mozilla/ is in xul-ext-dom-inspector 1:2.0.11-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/mozilla/extensions/
/usr/share/mozilla/extensions/toolkit@mozilla.org/
/usr/share/mozilla/extensions/toolkit@mozilla.org/inspector@mozilla.org
/usr/share/mozilla/extensions/{3550f703-e582-4d05-9a08-453d09bdfdc6}/
/usr/share/mozilla/extensions/{3550f703-e582-4d05-9a08-453d09bdfdc6}/inspector@mozilla.org
/usr/share/mozilla/extensions/{718e30fb-e89b-41dd-9da7-e25a45638b28}/
/usr/share/mozilla/extensions/{718e30fb-e89b-41dd-9da7-e25a45638b28}/inspector@mozilla.org
/usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/
/usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/inspector@mozilla.org
/usr/share/mozilla/extensions/{a23983c0-fd0e-11dc-95ff-0800200c9a66}/
/usr/share/mozilla/extensions/{a23983c0-fd0e-11dc-95ff-0800200c9a66}/inspector@mozilla.org
/usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/
/usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/inspector@mozilla.org