[css-pseudo-4] Remove ::selection support for 'outline'. w3c#3604

Author: fantasai

css-pseudo-4/Overview.bs

@@ -484,7 +484,6 @@ Styling Highlights</h3>
     <li>'background-color'
     <li>'cursor'
     <li>'caret-color'
-    <li>'outline' and its longhands
     <li>'text-decoration' and its associated properties
     <li>'text-shadow'
     <li>'stroke-color', 'fill-color', and 'stroke-width'
@@ -498,6 +497,7 @@ Styling Highlights</h3>
   applied to the text
   by the <a>originating element</a> and its ancestors and descendants.
 
+<!-- Add this back if for some reason someone wants to implement 'outline'?
   The outline, if supported, must be drawn
   around the union of the active portions of the <a>highlight overlay</a>
   precisely along the boundaries of those portions
@@ -506,8 +506,7 @@ Styling Highlights</h3>
   of any continuous or discontinuous range
   rather than piecing together varying styles of outline
   into a single shape.
-
-  ISSUE: Does anyone support 'outline' here? Is it wanted? Should we remove it from this list?
+-->
 
   Note: Historically (and at the time of writing)
   only 'color' and 'background-color' have been interoperably supported.