Bug 1595620 Add support for -webkit-font-feature-settings as an alias of font-feature-settings.r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D54159

--HG--
extra : moz-landing-system : lando

layout/style/test/property_database.js

@@ -11160,6 +11160,18 @@ var gCSSProperties = {
     alias_for: "box-sizing",
     subproperties: ["box-sizing"],
   },
+  "-webkit-font-feature-settings": {
+    domProp: "webkitFontFeatureSettings",
+    inherited: true,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    applies_to_first_letter: true,
+    applies_to_first_line: true,
+    applies_to_marker: true,
+    applies_to_placeholder: true,
+    applies_to_cue: true,
+    alias_for: "font-feature-settings",
+    subproperties: ["font-feature-settings"],
+  },
   "-webkit-box-flex": {
     domProp: "webkitBoxFlex",
     inherited: false,

servo/components/style/properties/counted_unknown_properties.py

@@ -16,7 +16,6 @@ COUNTED_UNKNOWN_PROPERTIES = [
     "-webkit-tap-highlight-color",
     "speak",
     "text-size-adjust",
-    "-webkit-font-feature-settings",
     "-webkit-user-drag",
     "size",
     "-webkit-clip-path",

servo/components/style/properties/longhands/font.mako.rs

@@ -171,7 +171,7 @@ ${helpers.predefined_type(
     engines="gecko",
     initial_value="computed::FontFeatureSettings::normal()",
     initial_specified_value="specified::FontFeatureSettings::normal()",
-    extra_prefixes="moz:layout.css.prefixes.font-features",
+    extra_prefixes="moz:layout.css.prefixes.font-features webkit",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-fonts/#propdef-font-feature-settings",
 )}