Bug 314240 – [Site Isolation] http/tests/security/mixedContent/insecure-css-with-secure-cookies-UpgradeMixedContent.html is flaky on macOS Site Isolation post-commit

• Component: New Bugs
• Status: RESOLVED FIXED

[Anthony Tarbinian]

The test is failing flakily with the following diff on macOS post-commit bots

```
--- /Volumes/Data/worker/Apple-Tahoe-Release-WK2-Site-Isolation-Tree-Tests/build/layout-test-results/http/tests/security/mixedContent/insecure-css-with-secure-cookies-UpgradeMixedContent-expected.txt
+++ /Volumes/Data/worker/Apple-Tahoe-Release-WK2-Site-Isolation-Tree-Tests/build/layout-test-results/http/tests/security/mixedContent/insecure-css-with-secure-cookies-UpgradeMixedContent-actual.txt
@@ -1,4 +1,2 @@
 CONSOLE MESSAGE: secureCookie=yes
-CONSOLE MESSAGE: The page at https://127.0.0.1:8443/security/mixedContent/resources/frame-with-insecure-css-secure-cookies.html requested insecure content from http://127.0.0.1:8080/security/resources/greenbox-hotspot5-4.cur. This content was automatically upgraded and should be served over HTTPS.
-
 This test opens a window that loads a secure style sheet with insecure cursor content after reading secure cookies. This should be allowed because loading of the insecure cursor does not pose a security risk since it can only affect the display.
```

[Radar WebKit Bug Importer]

<rdar://problem/176396263>

[Anthony Tarbinian]

Pull request: https://github.com/WebKit/WebKit/pull/64396

[EWS]

Committed 312746@main (a3d8b660f640): <https://commits.webkit.org/312746@main>

Reviewed commits have been landed. Closing PR #64396 and removing active labels.

[Anthony Tarbinian]

Several runs have been passing after this merged.

https://results.webkit.org/?suite=layout-tests&test=http%2Ftests%2Fsecurity%2FmixedContent%2Finsecure-css-with-secure-cookies-UpgradeMixedContent.html&flavor=site-isolation