fast/css/object-fit/object-fit-canvas.html keeps failing on EWS with a 0.01% image diff.
Marks as flakey image failure in https://trac.webkit.org/changeset/180991
This is a recent regression, but I don't know how to identify the culprit.
The first failure was on 2/28 (bug 140855 comment 8).
Maybe <http://trac.webkit.org/changeset/180815>?
No, it was flaky before that, just didn't happen to fail in a pattern that would make EWS post a comment.
The first failure was when processing bug 142078. Maybe <http://trac.webkit.org/changeset/180790>?
Created attachment 247910 [details] a diff from my machine I can reproduce with a lot larger diff on a hidpi machine. That started somewhere between 180791 and 180801, so it's very likely the same issue.
Wait, it's 1600x1200?! There is positively nothing in this range that could cause this; maybe I got it wrong due to flakiness.
My searching skills failed me. The test started to flakily fail when an expectation that it flakily fails was removed in <http://trac.webkit.org/changeset/180796>! It's still an issue that we should investigate soon though - WebKitTestRunner getting confused about the window size is very much not OK.
Looks like there are two issues here. 1. The test legitimately fails with small pixel differences on some machines. Looks like an ATI&Nvidia vs Intel graphics at a first glance. 2. When I run the test on my Mavericks machine, I get 1600x1200 results, and one of these looks like it's upscaled from 800x600.