With 25+ sessions the recents list virtualizes into its own nested
scroller inside the sidebar's scroll container. Both carried
overscroll-contain, so once the inner scroller hit a scroll boundary the
wheel gesture was consumed instead of chaining to the outer sidebar
scroller — read as a mid-list wheel dead-zone while scrollbar drag kept
working. Drop the containment on the inner scroller only; the outer
sidebar scroller keeps overscroll-contain so the gesture still never
escapes the sidebar.
Fixes#84964
Teknium
6b39ae490d