Following bug 262978, attachment-icon-from-file-extension.html should now properly work on WK2, including waiting for the icon to load before taking the screenshot. Previously the icon could be missing, leading to intermittent failures. However since then, this test cannot run on WK1 anymore, it times out. Based on some minimal logging, my guess at this time is that because of the "reftest-wait", there is no rendering at all, meaning the attachment rendering does not run even once, which is when the icon is first requested. Ideally it would be nice to trigger an initial rendering before the final screenshot rendering. If that's not possible, maybe the icon will have to be fetched eagerly, but that would modify the behavior. To be investigated further...
<rdar://problem/117193571>
Expanding this bug to cover all tests that would want to use reftest-wait on WK1. https://bugs.webkit.org/show_bug.cgi?id=263085 for fast/attachment/attachment-uti.html