Bug 199779 - Don't do async overflow scrolling for visibility:hidden scrollers
Summary: Don't do async overflow scrolling for visibility:hidden scrollers
Alias: None
Product: WebKit
Classification: Unclassified
Component: Scrolling (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Simon Fraser (smfr)
Keywords: InRadar
Depends on:
Reported: 2019-07-13 12:04 PDT by Simon Fraser (smfr)
Modified: 2019-07-13 15:40 PDT (History)
5 users (show)

See Also:

Patch (8.02 KB, patch)
2019-07-13 13:46 PDT, Simon Fraser (smfr)
dino: review+
Details | Formatted Diff | Diff

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Description Simon Fraser (smfr) 2019-07-13 12:04:27 PDT
If a scroller has visibility:hidden, don't trigger the async overflow scroll code path.

Some JS libraries make visibility:hidden scrollers (https://github.com/wnr/element-resize-detector) and we need to avoid the compositing cost.

I filed https://github.com/w3c/csswg-drafts/issues/4113 on this not being well-defined in CSS, and expect that to be resolved in a way that prevents scrolling.
Comment 1 Radar WebKit Bug Importer 2019-07-13 12:05:11 PDT
Comment 2 Simon Fraser (smfr) 2019-07-13 13:46:03 PDT
Created attachment 374081 [details]
Comment 3 Simon Fraser (smfr) 2019-07-13 15:34:57 PDT