It's been a default on GTK since https://commits.webkit.org/200076@main. It should fix a lot of WPE tests and let us reuse already existing baselines for passing GTK tests.
Pull request: https://github.com/WebKit/WebKit/pull/9513
Committed 259842@main (c92522eda224): <https://commits.webkit.org/259842@main> Reviewed commits have been landed. Closing PR #9513 and removing active labels.