[css-color-4] Update lab, lch browser tracking bugs

Author: svgeesus

css-color-4/Overview.bs

@@ -2842,7 +2842,18 @@ Specifying Lab and LCH: the ''lab()'' and ''lch()'' functional notations</h3>
 	<!-- lab rather than CIELab or whatever, for brevity -->
 
 	<!-- browser tracking bugs:
-		Chromium https://bugs.chromium.org/p/chromium/issues/detail?id=1026287
+		Chromium
+		https://bugs.chromium.org/p/chromium/issues/detail?id=1026287
+
+		WebKit
+		https://bugs.webkit.org/show_bug.cgi?id=205675
+		and
+		https://bugs.webkit.org/show_bug.cgi?id=220684
+
+		Gecko
+		https://bugzilla.mozilla.org/show_bug.cgi?id=1352757
+		and
+		https://bugzilla.mozilla.org/show_bug.cgi?id=1632548
 
 	-->