style: Implement CSS and rendering (but not copy/paste) support for the (non-standard) -webkit-text-security property

Differential Revision: https://phabricator.services.mozilla.com/D174951

components/style/properties/counted_unknown_properties.py

@@ -32,7 +32,6 @@ COUNTED_UNKNOWN_PROPERTIES = [
     "-webkit-print-color-adjust",
     "-webkit-mask-box-image",
     "-webkit-line-break",
-    "-webkit-text-security",
     "alignment-baseline",
     "-webkit-writing-mode",
     "baseline-shift",

components/style/properties/longhands/inherited_text.mako.rs

@@ -399,3 +399,12 @@ ${helpers.predefined_type(
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-color-adjust-1/#forced-color-adjust-prop",
 )}
+
+${helpers.single_keyword(
+    "-webkit-text-security",
+    "none circle disc square",
+    engines="gecko",
+    gecko_enum_prefix="StyleTextSecurity",
+    animation_value_type="discrete",
+    spec="https://drafts.csswg.org/css-text/#MISSING",
+)}