Proposal: intrinsic-size CSS property #4229
Description
http://tabatkins.github.io/specs/css-content-size/
This property specifies the size to reserve for elements which already have contain:size. contain:size without content-size is like having `content-size: 0px 0px. It's useful for providing placeholder sizes of subtrees in cases when it is not desirable to render the subtrees.
See also https://github.com/WICG/display-locking/blob/master/explainer-new.md for examples and background that helps to motivate this property.
Feedback appreciated!