[css-ui-4] Let user-select inherit normally to abspos

Author: frivoal

css-ui-4/Overview.bs

@@ -450,11 +450,11 @@ Omitted values are set to their initial values.
 		<ul>
 			<li>If the element is an <a>editable element</a>,
 			the computed value is ''element''
-			<li>Otherwise, if the element is not absolutely positioned
-			and the computed value of 'user-select' on the parent of this element is ''all'',
+			<li>Otherwise,
+			if the computed value of 'user-select' on the parent of this element is ''all'',
 			the computed value is ''all''
-			<li>Otherwise, if the element is not absolutely positioned
-			and the computed value of 'user-select' on the parent of this element is ''user-select/none'',
+			<li>Otherwise,
+			if the computed value of 'user-select' on the parent of this element is ''user-select/none'',
 			the computed value is ''user-select/none''
 			<li>Otherwise, the computed value is ''text''
 		</ul>
@@ -464,8 +464,6 @@ Omitted values are set to their initial values.
 		makes it possible to create what is effectively selective inheritance.
 		This was initially proposed by Microsoft in IE to introduce a behavior similar to inheritance
 		except that the ''element'' value does not inherit.
-		This also enables the behavior introduced by Mozilla in Firefox where absolutely positioned
-		children do not inherit from their parent.
 
 		<dt><dfn>text</dfn>
 		<dd>The element imposes no constraint on the selection.