[css-scrollbars] scrollbar-width should support custom measurements #6263
Description
SPEC: https://drafts.csswg.org/css-scrollbars-1/#scrollbar-width
The current spec only allows auto, thin and none for the scrollbar-width CSS property. The property should also support custom measurements in regular size units (px, pt, em, vw, ...).
Since the auto width is decided by the operating system and some operating systems do not provide a way for the user to adjust the appearance of the scrollbars (or at least have that ability hidden in some more tech-savvy area). The consequence of this is that if your OS has very thin scrollbars, there's no way to increase the width of the bars using CSS. This could be detrimental to users with certain accessibility issues.
My add-on Custom Scrollbars regularly receives email complaints about this ability not being available. The spec that Chromium-based browsers are using supports custom measurement units.