Add autofill pseudo-class (#5171)

- document :contains() before its removal
- remove JSONSelect val pseudo-class (guilty commit 8c808d0)

lib/reference/keywordSets.js

@@ -160,7 +160,7 @@ keywordSets.levelOneAndTwoPseudoElements = new Set([
 ]);
 
 // These are the ones that require double-colon notation
-keywordSets.levelThreePseudoElements = new Set([
+keywordSets.levelThreeAndUpPseudoElements = new Set([
 	'before',
 	'after',
 	'first-line',
@@ -206,7 +206,7 @@ keywordSets.vendorSpecificPseudoElements = new Set([
 
 keywordSets.pseudoElements = uniteSets(
 	keywordSets.levelOneAndTwoPseudoElements,
-	keywordSets.levelThreePseudoElements,
+	keywordSets.levelThreeAndUpPseudoElements,
 	keywordSets.vendorSpecificPseudoElements,
 	keywordSets.shadowTreePseudoElements,
 );
@@ -229,8 +229,13 @@ keywordSets.aNPlusBOfSNotationPseudoClasses = new Set(['nth-child', 'nth-last-ch
 keywordSets.otherPseudoClasses = new Set([
 	'active',
 	'any-link',
+	'autofill',
 	'blank',
 	'checked',
+	/*
+	  https://www.w3.org/Style/CSS/Test/CSS3/Selectors/20011105/html/tests/css3-modsel-85.html
+	  https://www.w3.org/Style/CSS/Test/CSS3/Selectors/20011105/html/tests/css3-modsel-84.html
+	*/
 	'contains',
 	'current',
 	'default',
@@ -273,7 +278,6 @@ keywordSets.otherPseudoClasses = new Set([
 	'target',
 	'user-error',
 	'user-invalid',
-	'val',
 	'valid',
 	'visited',
 ]);