Created attachment 396302 [details]
With async overflow scrolling enabled, the custom scrollbars on gmail are missing.
This happens any time we don't make backing store for the scroller; custom scrollbars are currently just painted.
Created attachment 396355 [details]
Comment on attachment 396355 [details]
View in context: https://bugs.webkit.org/attachment.cgi?id=396355&action=review
> bool RenderLayerBacking::requiresHorizontalScrollbarLayer() const
These functions seem a bit needless now. But maybe they're used externally?
Created attachment 396366 [details]
This is waiting on bug 210460.
Created attachment 396382 [details]
Committed r260074: <https://trac.webkit.org/changeset/260074>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 396382 [details].