Revert "Mark http/tests/security/xss-DENIED-cross-origin-stack-overflow.html non flaky"

This reverts commit f66e281273fada19d1f3794ea71423046414bab7.

Reason for revert: Test still flaky according to https://bugs.chromium.org/p/chromium/issues/detail?id=937546#c7

Original change's description:
> Mark http/tests/security/xss-DENIED-cross-origin-stack-overflow.html non flaky
> 
> The test doesn't seem to be flaky anymore. See dashboard:
> https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=webkit_layout_tests&tests=http%2Ftests%2Fsecurity%2Fxss-DENIED-cross-origin-stack-overflow.html
> 
> TBR=tsepez@chromium.org
> NOTRY=true
> 
> Bug: 937546
> Change-Id: Id9970a7b788538173d26b55e1586806bba09e37e
> Reviewed-on: https://chromium-review.googlesource.com/c/1498387
> Reviewed-by: Yi Gu <yigu@chromium.org>
> Commit-Queue: Yi Gu <yigu@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#637279}

TBR=tsepez@chromium.org,yigu@chromium.org

Change-Id: If5607652c072ab223f8c3f64aedf355bfc569b3d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 937546
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1501192
Reviewed-by: Darren Shen <shend@chromium.org>
Commit-Queue: Darren Shen <shend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#637470}
1 file changed