+++ This bug was initially created as a clone of Bug #1479050 +++ As discussed in https://bugzilla.mozilla.org/show_bug.cgi?id=1479050#c3 and https://bugzilla.mozilla.org/show_bug.cgi?id=1479050#c4, we are planning to add a new chrome-only API called document.createXULElement(el) as sugar around document.createElementNS(XUL_NS, el). Once we land that, we can migrated existing callers like - https://searchfox.org/mozilla-central/search?q=createElement&case=false&regexp=false&path= - https://searchfox.org/mozilla-central/search?q=createElementNS(%22http%3A%2F%2Fwww.mozilla&case=false&regexp=false&path= And then remove the const XUL_NS declarations (assuming they aren't used anywhere else in scope).

Comment on attachment 8999804 [details] Bug 1479538 - Rewrite non-test callers of document.createElementNS(XUL_NS, ...) to use document.createXULElement(...);r=paolo :Paolo Amadini has approved the revision.

Pushed by bgrinstead@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/7c59c72f3c8c Rewrite non-test callers of document.createElementNS(XUL_NS, ...) to use document.createXULElement(...);r=paolo

Commit pushed to master at https://github.com/mozilla/activity-stream https://github.com/mozilla/activity-stream/commit/56b2207f83de686bf42d549b8e797d9458ff1996 chore(mc): Port Bug 1479538 - Rewrite non-test callers of document.createElementNS(XUL_NS, ...) to use document.createXULElement(...);r=paolo (#4348)