/usr/ is in xul-ext-openinbrowser 1.15-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/
/usr/share/xul-ext/
/usr/share/xul-ext/openinbrowser/
/usr/share/xul-ext/openinbrowser/components/
/usr/share/xul-ext/openinbrowser/components/OpenInBrowser.js
/usr/share/xul-ext/openinbrowser/chrome/
/usr/share/xul-ext/openinbrowser/chrome/locale/
/usr/share/xul-ext/openinbrowser/chrome/locale/en-US/
/usr/share/xul-ext/openinbrowser/chrome/locale/en-US/openInBrowser.dtd
/usr/share/xul-ext/openinbrowser/chrome/locale/en-US/openInBrowser.properties
/usr/share/xul-ext/openinbrowser/chrome/locale/fr/
/usr/share/xul-ext/openinbrowser/chrome/locale/fr/openInBrowser.dtd
/usr/share/xul-ext/openinbrowser/chrome/locale/fr/openInBrowser.properties
/usr/share/xul-ext/openinbrowser/chrome/locale/ru/
/usr/share/xul-ext/openinbrowser/chrome/locale/ru/openInBrowser.dtd
/usr/share/xul-ext/openinbrowser/chrome/locale/ru/openInBrowser.properties
/usr/share/xul-ext/openinbrowser/chrome/locale/de-DE/
/usr/share/xul-ext/openinbrowser/chrome/locale/de-DE/openInBrowser.dtd
/usr/share/xul-ext/openinbrowser/chrome/locale/de-DE/openInBrowser.properties
/usr/share/xul-ext/openinbrowser/chrome/locale/sv-SE/
/usr/share/xul-ext/openinbrowser/chrome/locale/sv-SE/openInBrowser.dtd
/usr/share/xul-ext/openinbrowser/chrome/locale/sv-SE/openInBrowser.properties
/usr/share/xul-ext/openinbrowser/chrome/content/
/usr/share/xul-ext/openinbrowser/chrome/content/openInBrowser.js
/usr/share/xul-ext/openinbrowser/chrome/content/unknownContentTypeOverlay.js
/usr/share/xul-ext/openinbrowser/chrome/content/browserOverlay.xul
/usr/share/xul-ext/openinbrowser/chrome/content/browserOverlay.js
/usr/share/xul-ext/openinbrowser/chrome/content/unknownContentTypeOverlay.xul
/usr/share/xul-ext/openinbrowser/install.rdf
/usr/share/xul-ext/openinbrowser/chrome.manifest
/usr/share/doc/
/usr/share/doc/xul-ext-openinbrowser/
/usr/share/doc/xul-ext-openinbrowser/buildinfo_all.gz
/usr/share/doc/xul-ext-openinbrowser/changelog.Debian.gz
/usr/share/doc/xul-ext-openinbrowser/copyright
/usr/share/doc/xul-ext-openinbrowser/changelog.gz
/usr/share/doc/xul-ext-openinbrowser/README.md
/usr/share/mozilla/
/usr/share/mozilla/extensions/
/usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/
/usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/
/usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/openinbrowser@www.spasche.net
/usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/openinbrowser@www.spasche.net