- ScrollbarStyles now carries additional variables to support new
CSS scroll snapping attributes:
- scroll-snap-type / scroll-snap-type-x / scroll-snap-type-y
- scroll-snap-points-x / scroll-snap-points-y
- scroll-snap-destination
- (scroll-snap-coordinate does not apply to the scroll container)
- Simplified the constructor and operator== for ScrollbarStyles.
- Added SCROLL_SMOOTH_AUTO flag to nsIPresShell to enable selection of
scroll behavior through CSS.
- Updated Element and Window scrolling DOM methods to enable smooth scrolling
set through the scroll-behavior CSS property.
- Keyboard, scroll bar, mousewheel, and any other events that scroll smoothly
with the general.smoothScroll preference enabled will now scroll instantly
if the scroll frame has "scroll-behavior: instant" applied through CSS.
