The following tests fail due 1 pixel difference in the result.
I suspect that it's because some subpixel layout issue, similar to what causes css3/flexbox/line-wrapping.html to fail (see r148800)
(In reply to comment #0)
> The following tests fail due 1 pixel difference in the result.
Probably related to bug #117582
The expectation file for css3/flexbox/flex-item-contains-strict.html contains fail lines. The main issue with this test its that it requires support for the css containment spec as it uses <div style="contain: strict;" >. But WebKit still doesn't support that: see bug 172026
Note that this test can be removed in favor of WPT https://wpt.live/css/css-flexbox/flex-item-contains-strict.html once imported (its basically the same test)
I'm retitling this, the bug doesn't seems GTK specific.
Also I'm removing the test css3/flexbox/flex-item-contains-strict.html in favor of imported/w3c/web-platform-tests/css/css-flexbox/flex-item-contains-strict.html (its basically the same test) in bug 191460