[META] min-width/height should default to auto for flexbox and grid items

• Component: CSS
• Status: RESOLVED FIXED

[Sergio Villar Senin]

According to Flexbox[1] and Grid Layout[2] specs, the default value for the min-width/height properties for the flex/grid items should be 'auto'.

For flexbox items the default value was changed from min-content to 0 in https://bugs.webkit.org/show_bug.cgi?id=111790 and later reported as a regression https://bugs.webkit.org/show_bug.cgi?id=114566.

Since then the spec has changed and now it's clearly specified both the default value for those properties and also how to compute the minimum size for flex/grid items.

[1] http://dev.w3.org/csswg/css-flexbox/#min-size-auto
[2] http://dev.w3.org/csswg/css-grid/#min-size-auto

[Sergio Villar Senin]

This requires intrinsic sizes support for height, min-height and max-heigt, see bug 113610.

The fix involves merging the following Blink change logs:

* for flexbox
- https://crrev.com/193665
- https://crrev.com/194062
- https://crrev.com/195930

* for grid
- https://crrev.com/194408 
- https://crrev.com/194863

* for both
https://crrev.com/194887

That's why I'm converting this into a meta-bug to land flex and grid changes independently

[Sergio Villar Senin]

Closing as all dependent bugs were fixed.