Bug 198364

Summary: [Async overflow scrolling] Backing store attachment logic for composited-inside-scroller needs to account for non-ancestor scrollers
Product: WebKit Reporter: Simon Fraser (smfr) <simon.fraser>
Component: ScrollingAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: koivisto, simon.fraser, thorton, webkit-bug-importer, zalan
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://bugs.webkit.org/show_bug.cgi?id=198363

Description Simon Fraser (smfr) 2019-05-29 19:49:38 PDT 
We generally inflate the coverage rect for composited scrollers (e.g. bug 198363) so that composited descendants get backing store attachment before they are scrolled into view.

However, with a non-stacking context scrollers, descendants don't see the scroller's coverage rect, so we need another way to inflate their coverage.
Comment 1 Radar WebKit Bug Importer 2019-05-29 19:51:47 PDT 
<rdar://problem/51248288>