[selectors-4] Define :-webkit-autofill #7257

Author: fantasai

selectors-4/Overview.bs

@@ -3923,14 +3923,17 @@ Appendix A: Guidance on Mapping Source Documents &amp; Data to an Element Tree</
 
 
 <h2 id="compat">
-Appendix B: Obsolete but Required Parsing Quirks for Web Compat</h2>
+Appendix B: Obsolete but Required <code>-webkit-</code> Parsing Quirks for Web Compat</h2>
 
 	<em>This appendix is normative.</em>
 
 	Due to legacy Web-compat constraints,
 	user agents expecting to parse Web documents must support the following features:
 
-	* All [=pseudo-elements=] whose names begin with the string “-webkit-”
+	* '':-webkit-autofill'' must be treated as a [=legacy selector alias=] of '':autofill''.
+		<!-- expand this into a table or something if we add any more aliases -->
+
+	* All other [=pseudo-elements=] whose names begin with the string “-webkit-”
 		(matched <a>ASCII case-insensitively</a>)
 		and that are not functional notations
 		must be treated as valid at parse time.