Created attachment 366772 [details] Test file The attached test fails to get an async scrollable frame when run as a layout test. It works fine in MobileSafari. Makes it hard to test.
<rdar://problem/49628883>
settings().asyncFrameScrollingEnabled() is false in subframes in WTR.
Oh, InjectedBundle::beginTesting() turns of async frame scrolling. This is different from how we turn off async overflow scrolling.
Created attachment 366789 [details] Patch
Comment on attachment 366789 [details] Patch Clearing flags on attachment: 366789 Committed r243927: <https://trac.webkit.org/changeset/243927>
All reviewed patches have been landed. Closing bug.