Bug 261300

Summary: [iOS] Have iOS use the normal "have overlay scrollbars" behavior
Product: WebKit Reporter: Simon Fraser (smfr) <simon.fraser>
Component: ScrollingAssignee: Simon Fraser (smfr) <simon.fraser>
Status: NEW ---    
Severity: Normal CC: a_protyasha, simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: Safari 16   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://bugs.webkit.org/show_bug.cgi?id=261299

Description Simon Fraser (smfr) 2023-09-07 15:24:05 PDT 
There are some historical #idfefs for iOS that were done the iOS was the only platform to have overlay scrollbars, before these came to macOS, but these cause some surprising behavior in layout tests, particularly because RenderLayerScrollableArea::showsOverflowControls() can return a different result depending on whether we use composited scrolling.
Comment 1 Radar WebKit Bug Importer 2023-09-07 15:26:40 PDT 
<rdar://problem/115139613>
Comment 2 Simon Fraser (smfr) 2023-09-07 15:41:40 PDT 
Pull request: https://github.com/WebKit/WebKit/pull/17560
Comment 3 Simon Fraser (smfr) 2023-09-13 19:24:46 PDT 
This isn't so simple. Lots of nasty interactions between mock scrollbars, custom scrollbars etc.