The smooth-wheel feature (#3974, closing #3966) intercepts mouse-wheel
events in scroll mode: it makes the wheel listener non-passive,
preventDefault()s the native scroll, and replays the delta through a
main-thread rAF animation against the renderer container.
That regressed normal mouse scrolling on Windows (#4130): fast wheel
bursts were discarded entirely, and the JS replay is structurally worse
than native scrolling -- a non-passive wheel listener forces every wheel
event (mouse and trackpad) off the compositor thread, and the
postMessage hop plus main-thread animation add latency and jank that
native compositor scrolling does not have.
High-resolution scrolling (e.g. Logitech MX Master, the mouse in #3966)
needs no special API: the OS/driver just delivers regular wheel events
with smaller, more frequent deltas, and the browser scrolls them
natively. #3966's own report ("smooth scrolling works with all
applications apart from yours") points at the interception, not a
missing capability. Restore native wheel scrolling in scroll mode.
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Huang Xin
f5e729a174