Revert of Deprecate 'intrinsic' and 'min-intrinsic' CSS keywords

LayoutTests/fast/css-intrinsic-dimensions/resources/width-keyword-classes.css

 /*
     Take every possible line break so the box width is the width of largest
     unbreakable line box.
 */
 .min-content {
+    /* Webkit, but not actually implemented outside deprecated flexbox */
+    width: min-intrinsic;
     width: -webkit-min-content;
     width: -moz-min-content;
     width: min-content;
 }
 
 .max-content {
     width: -webkit-max-content;
     width: -moz-max-content;
     width: max-content;
 }
 
 /*
     Identical to auto except for elements with an instrinsic width like an
     img where this overrides the intrinsic width to get regular block "auto".
 */
 .fill-available {
     width: -webkit-fill-available;
     /* Firefox is missing the fill- prefix because they followed an older spec */
     width: -moz-available;
     width: fill-available;
 }
 
 /*
    Shrink wrap just like floating.
    max(min-content, min(max-content, fill-available))
 */
 .fit-content {
+    /* Webkit, but only outside a deprecated flexbox. */
+    width: intrinsic;
     width: -webkit-fit-content;
     width: -moz-fit-content;
     width: fit-content;
 }
 
 .max-width-min-content {
     max-width: -webkit-min-content;
     max-width: -moz-min-content;
     max-width: min-content;
 }
 
 .max-width-max-content {
     max-width: -webkit-max-content;
     max-width: -moz-max-content;
     max-width: max-content;
 }
 
 .max-width-fill-available {
     max-width: -webkit-fill-available;
     max-width: -moz-available;
     max-width: fill-available;
 }
 
 .max-width-fit-content {
+    max-width: intrinsic;
     max-width: -webkit-fit-content;
     max-width: -moz-fit-content;
     max-width: fit-content;
 }
 
 .min-width-min-content {
     min-width: -webkit-min-content;
     min-width: -moz-min-content;
     min-width: min-content;
 }
 
 .min-width-max-content {
     min-width: -webkit-max-content;
     min-width: -moz-max-content;
     min-width: max-content;
 }
 
 .min-width-fill-available {
     min-width: -webkit-fill-available;
     min-width: -moz-available;
     min-width: fill-available;
 }
 
 .min-width-fit-content {
+    min-width: intrinsic;
     min-width: -webkit-fit-content;
     min-width: -moz-fit-content;
     min-width: fit-content;
 }