[css-flexbox] When omitted from the flex shorthand the flex-basis value is... #5742
Description
Per spec it should be 0, but it used to be 0% and it was never changed in browsers, see https://drafts.csswg.org/css-flexbox/#change-201505-substantive:
Is there value in making this change? What compat issues can it cause other than serialization @fantasai?
Do other browsers want to make the change? Otherwise that change should maybe be reverted?