Cross origin isolation doesn't happen when going from an HTTP URL to a HTTPS one with COOP+COEP.
The COOP header is ignored for non-secure contexts. However, our check is slightly wrong and we always check if the source of the navigation is a secure context or not.
Created attachment 437058 [details]
Committed r281935 (241244@main): <https://commits.webkit.org/241244@main>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 437058 [details].
The test added in this change is flaky on GTK, sometimes passing and sometimes failing like this:
@@ -1,3 +1,3 @@
-PASS Make sure that COOP causes a browsing context group switch when navigating from a secure context to a non-secure one
+FAIL Make sure that COOP causes a browsing context group switch when navigating from a secure context to a non-secure one assert_true: Window should be closed expected true got false