===Running cross-origin mochitests in Treeherder===
TODO
* currently supported for mochitestMochitest-plain jobswith cross-origin and fission mode enabled can be run on treeherder. Search for "M-fis-xorigin" using the [https://firefox-source-docs.mozilla.org/tools/try/selectors/fuzzy.html try fuzzy selector] (./mach try fuzzy). * [https://bugzilla.mozilla.org/show_bug.cgi?id=1647720 Bug 1647720] request for enabling Currently enabled on tier2
===Tips for debugging broken xorigin mochitests===
