REGRESSION(r205315): LayoutTest fast/dom/Attr/access-after-element-destruction.html frequently crashes

[Ryan Haddad]

LayoutTest fast/dom/Attr/access-after-element-destruction.html frequently crashes

Full crashlog:
https://build.webkit.org/results/Apple%20Yosemite%20Debug%20WK1%20(Tests)/r205361%20(15790)/fast/dom/Attr/access-after-element-destruction-crash-log.txt

Failing run:
https://build.webkit.org/results/Apple%20Yosemite%20Debug%20WK1%20(Tests)/r205361%20(15790)/results.html

Flakiness dashboard:
https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=fast%2Fdom%2FAttr%2Faccess-after-element-destruction.html

[Ryan Haddad]

Looking at the dashboard, this may have regressed with https://trac.webkit.org/changeset/205315

[Alexey Proskuryakov]

This being memory corruption on tests, we need to resolve it ASAP.

[Chris Dumez]

Seems to be related to custom elements. Ryosuke, can you take a look?

[Alexey Proskuryakov]

This is expected to be fixed with the rollout in <https://trac.webkit.org/r205383>, moving to RESOLVED until proven otherwise.