The [[ https://searchfox.org/mozilla-central/rev/559b25eb41c1cbffcb90a34e008b8288312fcd25/dom/base/nsGlobalWindowInner.cpp#5070-5071 | assertion ]] is called in a [[ https://searchfox.org/mozilla-central/rev/559b25eb41c1cbffcb90a34e008b8288312fcd25/dom/storage/StorageNotifierService.cpp#86-87 | runnable ]], the condition was previously bailed out by the same [[ https://searchfox.org/mozilla-central/rev/559b25eb41c1cbffcb90a34e008b8288312fcd25/dom/storage/StorageNotifierService.cpp#78-81 | expression ]]. Dynamic FPI may potentially relaxed the effective storage principal from intrinsic storage principal to node principal, when it happened during the asynchrnous event, it will end up raise the assertion. Differential Revision: https://phabricator.services.mozilla.com/D78017