Currently, Chrome updates the cursor and hover states after scrolling stops (see MouseEventManager::DispatchFakeMouseMoveEventSoon). This causes a hit test and potentially blocks main thread scrolling if the lifecycle update is expensive.

It's been mentioned Edge doesn't update cursors/hover at all unless the mouse physically moves. This could help us reduce jank.

Action items for this bug:

1) Confirm Edge's behavior
2) Determine how web-compatible this change might be
3) Implement it behind a flag