From 805b20a4faa8a3aa9d9271ae97a5b23bc35a1ad0 Mon Sep 17 00:00:00 2001
From: Oriol Brufau <oriol-bugzilla@hotmail.com>
Date: Tue, 19 Mar 2024 23:10:39 +0000
Subject: [PATCH] Bug 1886218 - Unify servo-2013 and servo-2020. r=emilio

This imports https://github.com/servo/stylo/commit/c9ca340 from Servo,
with minor adjustments for D187431, 'baseline-source', and to ensure
that Firefox still compiles.

Differential Revision: https://phabricator.services.mozilla.com/D205110
---
 servo/components/style/Cargo.toml             |  2 -
 servo/components/style/build.rs               | 12 ++--
 servo/components/style/properties/build.py    | 14 ++--
 servo/components/style/properties/data.py     | 71 ++++++-------------
 .../style/properties/helpers.mako.rs          |  6 +-
 .../properties/longhands/background.mako.rs   | 18 ++---
 .../style/properties/longhands/border.mako.rs | 20 +++---
 .../style/properties/longhands/box.mako.rs    | 46 ++++++------
 .../style/properties/longhands/column.mako.rs | 13 ++--
 .../properties/longhands/counters.mako.rs     |  8 ++-
 .../properties/longhands/effects.mako.rs      | 12 ++--
 .../style/properties/longhands/font.mako.rs   | 14 ++--
 .../longhands/inherited_box.mako.rs           | 13 ++--
 .../longhands/inherited_table.mako.rs         | 12 ++--
 .../longhands/inherited_text.mako.rs          | 32 ++++-----
 .../properties/longhands/inherited_ui.mako.rs |  4 +-
 .../style/properties/longhands/list.mako.rs   | 17 ++---
 .../style/properties/longhands/margin.mako.rs |  2 +-
 .../properties/longhands/outline.mako.rs      | 10 ++-
 .../properties/longhands/padding.mako.rs      |  2 +-
 .../properties/longhands/position.mako.rs     | 65 +++++++++--------
 .../style/properties/longhands/table.mako.rs  |  3 +-
 .../style/properties/longhands/text.mako.rs   | 12 ++--
 .../style/properties/longhands/ui.mako.rs     | 30 ++++----
 .../style/properties/properties.mako.rs       |  9 ++-
 .../properties/shorthands/background.mako.rs  |  4 +-
 .../properties/shorthands/border.mako.rs      | 19 ++---
 .../style/properties/shorthands/box.mako.rs   |  2 +-
 .../properties/shorthands/column.mako.rs      |  4 +-
 .../style/properties/shorthands/font.mako.rs  |  5 +-
 .../style/properties/shorthands/list.mako.rs  | 21 +++++-
 .../properties/shorthands/margin.mako.rs      |  6 +-
 .../properties/shorthands/outline.mako.rs     |  2 +-
 .../properties/shorthands/padding.mako.rs     |  6 +-
 .../properties/shorthands/position.mako.rs    | 14 ++--
 .../style/properties/shorthands/text.mako.rs  |  2 +-
 .../style/properties/shorthands/ui.mako.rs    |  4 +-
 servo/components/style/style_adjuster.rs      |  8 +--
 servo/components/style/traversal.rs           |  4 +-
 .../style/values/generics/counters.rs         | 14 +---
 .../components/style/values/generics/image.rs |  4 +-
 .../components/style/values/specified/box.rs  | 44 +-----------
 .../style/values/specified/counters.rs        | 11 +--
 .../style/values/specified/image.rs           |  2 +-
 .../components/style/values/specified/text.rs |  7 +-
 45 files changed, 280 insertions(+), 350 deletions(-)

diff --git a/servo/components/style/Cargo.toml b/servo/components/style/Cargo.toml
index acf1bcf6fee9..d6e37d49030a 100644
--- a/servo/components/style/Cargo.toml
+++ b/servo/components/style/Cargo.toml
@@ -21,8 +21,6 @@ gecko = ["nsstring", "serde", "style_traits/gecko", "bindgen", "regex", "toml",
 servo = ["serde", "style_traits/servo", "servo_atoms", "servo_config", "html5ever",
          "cssparser/serde", "encoding_rs", "malloc_size_of/servo", "arrayvec/use_union",
          "servo_url", "string_cache", "to_shmem/servo", "servo_arc/servo"]
-servo-layout-2013 = []
-servo-layout-2020 = []
 gecko_debug = []
 gecko_refcount_logging = []
 
diff --git a/servo/components/style/build.rs b/servo/components/style/build.rs
index 2247e876181d..4b27edbe2c32 100644
--- a/servo/components/style/build.rs
+++ b/servo/components/style/build.rs
@@ -71,16 +71,12 @@ fn generate_properties(engine: &str) {
 fn main() {
     let gecko = cfg!(feature = "gecko");
     let servo = cfg!(feature = "servo");
-    let l2013 = cfg!(feature = "servo-layout-2013");
-    let l2020 = cfg!(feature = "servo-layout-2020");
-    let engine = match (gecko, servo, l2013, l2020) {
-        (true, false, false, false) => "gecko",
-        (false, true, true, false) => "servo-2013",
-        (false, true, false, true) => "servo-2020",
+    let engine = match (gecko, servo) {
+        (true, false) => "gecko",
+        (false, true) => "servo",
         _ => panic!(
             "\n\n\
-             The style crate requires enabling one of its 'servo' or 'gecko' feature flags \
-             and, in the 'servo' case, one of 'servo-layout-2013' or 'servo-layout-2020'.\
+             The style crate requires enabling one of its 'servo' or 'gecko' feature flags. \
              \n\n"
         ),
     };
diff --git a/servo/components/style/properties/build.py b/servo/components/style/properties/build.py
index 42121a4eae46..f5307927a352 100644
--- a/servo/components/style/properties/build.py
+++ b/servo/components/style/properties/build.py
@@ -49,7 +49,7 @@ STYLE_STRUCT_LIST = [
 
 def main():
     usage = (
-        "Usage: %s [ servo-2013 | servo-2020 | gecko ] [ style-crate | geckolib <template> | html ]"
+        "Usage: %s [ servo | gecko ] [ style-crate | geckolib <template> | html ]"
         % sys.argv[0]
     )
     if len(sys.argv) < 3:
@@ -57,7 +57,7 @@ def main():
     engine = sys.argv[1]
     output = sys.argv[2]
 
-    if engine not in ["servo-2013", "servo-2020", "gecko"] or output not in [
+    if engine not in ["servo", "gecko"] or output not in [
         "style-crate",
         "geckolib",
         "html",
@@ -101,17 +101,13 @@ def main():
             rust = render(template, data=properties)
             write(OUT_DIR, "gecko_properties.rs", rust)
 
-        if engine in ["servo-2013", "servo-2020"]:
-            if engine == "servo-2013":
-                pref_attr = "servo_2013_pref"
-            if engine == "servo-2020":
-                pref_attr = "servo_2020_pref"
+        if engine == "servo":
             properties_dict = {
                 kind: {
-                    p.name: {"pref": getattr(p, pref_attr)}
+                    p.name: {"pref": getattr(p, "servo_pref")}
                     for prop in properties_list
                     if prop.enabled_in_content()
-                    for p in [prop] + prop.alias
+                    for p in [prop] + prop.aliases
                 }
                 for kind, properties_list in [
                     ("longhands", properties.longhands),
diff --git a/servo/components/style/properties/data.py b/servo/components/style/properties/data.py
index 093f1cb75f93..443227f02d12 100644
--- a/servo/components/style/properties/data.py
+++ b/servo/components/style/properties/data.py
@@ -176,11 +176,9 @@ class Keyword(object):
         gecko_enum_prefix=None,
         custom_consts=None,
         extra_gecko_values=None,
-        extra_servo_2013_values=None,
-        extra_servo_2020_values=None,
+        extra_servo_values=None,
         gecko_aliases=None,
-        servo_2013_aliases=None,
-        servo_2020_aliases=None,
+        servo_aliases=None,
         gecko_strip_moz_prefix=None,
         gecko_inexhaustive=None,
     ):
@@ -196,11 +194,9 @@ class Keyword(object):
         )
         self.gecko_enum_prefix = gecko_enum_prefix
         self.extra_gecko_values = (extra_gecko_values or "").split()
-        self.extra_servo_2013_values = (extra_servo_2013_values or "").split()
-        self.extra_servo_2020_values = (extra_servo_2020_values or "").split()
+        self.extra_servo_values = (extra_servo_values or "").split()
         self.gecko_aliases = parse_aliases(gecko_aliases or "")
-        self.servo_2013_aliases = parse_aliases(servo_2013_aliases or "")
-        self.servo_2020_aliases = parse_aliases(servo_2020_aliases or "")
+        self.servo_aliases = parse_aliases(servo_aliases or "")
         self.consts_map = {} if custom_consts is None else custom_consts
         self.gecko_strip_moz_prefix = (
             True if gecko_strip_moz_prefix is None else gecko_strip_moz_prefix
@@ -210,20 +206,16 @@ class Keyword(object):
     def values_for(self, engine):
         if engine == "gecko":
             return self.values + self.extra_gecko_values
-        elif engine == "servo-2013":
-            return self.values + self.extra_servo_2013_values
-        elif engine == "servo-2020":
-            return self.values + self.extra_servo_2020_values
+        elif engine == "servo":
+            return self.values + self.extra_servo_values
         else:
             raise Exception("Bad engine: " + engine)
 
     def aliases_for(self, engine):
         if engine == "gecko":
             return self.gecko_aliases
-        elif engine == "servo-2013":
-            return self.servo_2013_aliases
-        elif engine == "servo-2020":
-            return self.servo_2020_aliases
+        elif engine == "servo":
+            return self.servo_aliases
         else:
             raise Exception("Bad engine: " + engine)
 
@@ -289,8 +281,7 @@ class Property(object):
         self,
         name,
         spec,
-        servo_2013_pref,
-        servo_2020_pref,
+        servo_pref,
         gecko_pref,
         enabled_in,
         rule_types_allowed,
@@ -304,8 +295,7 @@ class Property(object):
         self.spec = spec
         self.ident = to_rust_ident(name)
         self.camel_case = to_camel_case(self.ident)
-        self.servo_2013_pref = servo_2013_pref
-        self.servo_2020_pref = servo_2020_pref
+        self.servo_pref = servo_pref
         self.gecko_pref = gecko_pref
         self.rule_types_allowed = rule_values_from_arg(rule_types_allowed)
         # For enabled_in, the setup is as follows:
@@ -329,10 +319,8 @@ class Property(object):
     def experimental(self, engine):
         if engine == "gecko":
             return bool(self.gecko_pref)
-        elif engine == "servo-2013":
-            return bool(self.servo_2013_pref)
-        elif engine == "servo-2020":
-            return bool(self.servo_2020_pref)
+        elif engine == "servo":
+            return bool(self.servo_pref)
         else:
             raise Exception("Bad engine: " + engine)
 
@@ -364,8 +352,7 @@ class Longhand(Property):
         animation_value_type=None,
         keyword=None,
         predefined_type=None,
-        servo_2013_pref=None,
-        servo_2020_pref=None,
+        servo_pref=None,
         gecko_pref=None,
         enabled_in="content",
         need_index=False,
@@ -390,8 +377,7 @@ class Longhand(Property):
             self,
             name=name,
             spec=spec,
-            servo_2013_pref=servo_2013_pref,
-            servo_2020_pref=servo_2020_pref,
+            servo_pref=servo_pref,
             gecko_pref=gecko_pref,
             enabled_in=enabled_in,
             rule_types_allowed=rule_types_allowed,
@@ -518,16 +504,8 @@ class Longhand(Property):
     def may_be_disabled_in(self, shorthand, engine):
         if engine == "gecko":
             return self.gecko_pref and self.gecko_pref != shorthand.gecko_pref
-        elif engine == "servo-2013":
-            return (
-                self.servo_2013_pref
-                and self.servo_2013_pref != shorthand.servo_2013_pref
-            )
-        elif engine == "servo-2020":
-            return (
-                self.servo_2020_pref
-                and self.servo_2020_pref != shorthand.servo_2020_pref
-            )
+        elif engine == "servo":
+            return self.servo_pref and self.servo_pref != shorthand.servo_pref
         else:
             raise Exception("Bad engine: " + engine)
 
@@ -659,8 +637,7 @@ class Shorthand(Property):
         name,
         sub_properties,
         spec=None,
-        servo_2013_pref=None,
-        servo_2020_pref=None,
+        servo_pref=None,
         gecko_pref=None,
         enabled_in="content",
         rule_types_allowed=DEFAULT_RULES,
@@ -672,8 +649,7 @@ class Shorthand(Property):
             self,
             name=name,
             spec=spec,
-            servo_2013_pref=servo_2013_pref,
-            servo_2020_pref=servo_2020_pref,
+            servo_pref=servo_pref,
             gecko_pref=gecko_pref,
             enabled_in=enabled_in,
             rule_types_allowed=rule_types_allowed,
@@ -704,8 +680,7 @@ class Alias(object):
         self.original = original
         self.enabled_in = original.enabled_in
         self.animatable = original.animatable
-        self.servo_2013_pref = original.servo_2013_pref
-        self.servo_2020_pref = original.servo_2020_pref
+        self.servo_pref = original.servo_pref
         self.gecko_pref = gecko_pref
         self.rule_types_allowed = original.rule_types_allowed
         self.flags = original.flags
@@ -722,10 +697,8 @@ class Alias(object):
     def experimental(self, engine):
         if engine == "gecko":
             return bool(self.gecko_pref)
-        elif engine == "servo-2013":
-            return bool(self.servo_2013_pref)
-        elif engine == "servo-2020":
-            return bool(self.servo_2020_pref)
+        elif engine == "servo":
+            return bool(self.servo_pref)
         else:
             raise Exception("Bad engine: " + engine)
 
@@ -856,7 +829,7 @@ def _add_logical_props(data, props):
     groups = set()
     for prop in props:
         if prop not in data.longhands_by_name:
-            assert data.engine in ["servo-2013", "servo-2020"]
+            assert data.engine == "servo"
             continue
         prop = data.longhands_by_name[prop]
         if prop.logical_group:
diff --git a/servo/components/style/properties/helpers.mako.rs b/servo/components/style/properties/helpers.mako.rs
index 968a97aa00e8..82998632ca21 100644
--- a/servo/components/style/properties/helpers.mako.rs
+++ b/servo/components/style/properties/helpers.mako.rs
@@ -594,11 +594,9 @@
             'gecko_constant_prefix',
             'gecko_enum_prefix',
             'extra_gecko_values',
-            'extra_servo_2013_values',
-            'extra_servo_2020_values',
+            'extra_servo_values',
             'gecko_aliases',
-            'servo_2013_aliases',
-            'servo_2020_aliases',
+            'servo_aliases',
             'custom_consts',
             'gecko_inexhaustive',
             'gecko_strip_moz_prefix',
diff --git a/servo/components/style/properties/longhands/background.mako.rs b/servo/components/style/properties/longhands/background.mako.rs
index 48270f748eb3..97967cb0892a 100644
--- a/servo/components/style/properties/longhands/background.mako.rs
+++ b/servo/components/style/properties/longhands/background.mako.rs
@@ -10,7 +10,7 @@ ${helpers.predefined_type(
     "background-color",
     "Color",
     "computed::Color::TRANSPARENT_BLACK",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="SpecifiedValue::transparent()",
     spec="https://drafts.csswg.org/css-backgrounds/#background-color",
     animation_value_type="AnimatedColor",
@@ -23,7 +23,7 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "background-image",
     "Image",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::Image::None",
     initial_specified_value="specified::Image::None",
     spec="https://drafts.csswg.org/css-backgrounds/#the-background-image",
@@ -38,7 +38,7 @@ ${helpers.predefined_type(
         "background-position-" + axis,
         "position::" + direction + "Position",
         "computed::LengthPercentage::zero_percent()",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         initial_specified_value="SpecifiedValue::initial_specified_value()",
         spec="https://drafts.csswg.org/css-backgrounds-4/#propdef-background-position-" + axis,
         animation_value_type="ComputedValue",
@@ -52,7 +52,7 @@ ${helpers.predefined_type(
     "background-repeat",
     "BackgroundRepeat",
     "computed::BackgroundRepeat::repeat()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::BackgroundRepeat::repeat()",
     animation_value_type="discrete",
     vector=True,
@@ -62,8 +62,8 @@ ${helpers.predefined_type(
 
 ${helpers.single_keyword(
     "background-attachment",
-    "scroll" + (" fixed" if engine in ["gecko", "servo-2013"] else "") + (" local" if engine == "gecko" else ""),
-    engines="gecko servo-2013 servo-2020",
+    "scroll fixed" + (" local" if engine == "gecko" else ""),
+    engines="gecko servo",
     vector=True,
     gecko_enum_prefix="StyleImageLayerAttachment",
     spec="https://drafts.csswg.org/css-backgrounds/#the-background-attachment",
@@ -74,7 +74,7 @@ ${helpers.single_keyword(
 ${helpers.single_keyword(
     "background-clip",
     "border-box padding-box content-box",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     extra_gecko_values="text",
     vector=True, extra_prefixes="webkit",
     gecko_enum_prefix="StyleGeometryBox",
@@ -87,7 +87,7 @@ ${helpers.single_keyword(
 ${helpers.single_keyword(
     "background-origin",
     "padding-box border-box content-box",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     vector=True, extra_prefixes="webkit",
     gecko_enum_prefix="StyleGeometryBox",
     gecko_inexhaustive=True,
@@ -99,7 +99,7 @@ ${helpers.single_keyword(
 ${helpers.predefined_type(
     "background-size",
     "BackgroundSize",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::BackgroundSize::auto()",
     initial_specified_value="specified::BackgroundSize::auto()",
     spec="https://drafts.csswg.org/css-backgrounds/#the-background-size",
diff --git a/servo/components/style/properties/longhands/border.mako.rs b/servo/components/style/properties/longhands/border.mako.rs
index 4d0676f67857..0ea6227412f6 100644
--- a/servo/components/style/properties/longhands/border.mako.rs
+++ b/servo/components/style/properties/longhands/border.mako.rs
@@ -23,7 +23,7 @@
     ${helpers.predefined_type(
         "border-%s-color" % side_name, "Color",
         "computed_value::T::currentcolor()",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         aliases=maybe_moz_logical_alias(engine, side, "-moz-border-%s-color"),
         spec=maybe_logical_spec(side, "color"),
         animation_value_type="AnimatedColor",
@@ -37,7 +37,7 @@
     ${helpers.predefined_type(
         "border-%s-style" % side_name, "BorderStyle",
         "specified::BorderStyle::None",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         aliases=maybe_moz_logical_alias(engine, side, "-moz-border-%s-style"),
         spec=maybe_logical_spec(side, "style"),
         animation_value_type="discrete" if not is_logical else "none",
@@ -50,7 +50,7 @@
         "border-%s-width" % side_name,
         "BorderSideWidth",
         "app_units::Au::from_px(3)",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         aliases=maybe_moz_logical_alias(engine, side, "-moz-border-%s-width"),
         spec=maybe_logical_spec(side, "width"),
         animation_value_type="NonNegativeLength",
@@ -76,7 +76,7 @@
         "BorderCornerRadius",
         "computed::BorderCornerRadius::zero()",
         "parse",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         extra_prefixes=prefixes,
         spec=maybe_logical_spec(corner, "radius"),
         boxed=True,
@@ -111,13 +111,13 @@ ${helpers.single_keyword(
 ${helpers.predefined_type(
     "border-image-source",
     "Image",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::Image::None",
     initial_specified_value="specified::Image::None",
     spec="https://drafts.csswg.org/css-backgrounds/#the-background-image",
     vector=False,
     animation_value_type="discrete",
-    boxed=engine == "servo-2013",
+    boxed=engine == "servo",
     ignored_when_colors_disabled=True,
     affects="paint",
 )}
@@ -125,7 +125,7 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "border-image-outset",
     "NonNegativeLengthOrNumberRect",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="generics::rect::Rect::all(computed::NonNegativeLengthOrNumber::zero())",
     initial_specified_value="generics::rect::Rect::all(specified::NonNegativeLengthOrNumber::zero())",
     spec="https://drafts.csswg.org/css-backgrounds/#border-image-outset",
@@ -138,7 +138,7 @@ ${helpers.predefined_type(
     "border-image-repeat",
     "BorderImageRepeat",
     "computed::BorderImageRepeat::stretch()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::BorderImageRepeat::stretch()",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-backgrounds/#the-border-image-repeat",
@@ -148,7 +148,7 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "border-image-width",
     "BorderImageWidth",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::BorderImageWidth::all(computed::BorderImageSideWidth::one())",
     initial_specified_value="specified::BorderImageWidth::all(specified::BorderImageSideWidth::one())",
     spec="https://drafts.csswg.org/css-backgrounds/#border-image-width",
@@ -160,7 +160,7 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "border-image-slice",
     "BorderImageSlice",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::BorderImageSlice::hundred_percent()",
     initial_specified_value="specified::BorderImageSlice::hundred_percent()",
     spec="https://drafts.csswg.org/css-backgrounds/#border-image-slice",
diff --git a/servo/components/style/properties/longhands/box.mako.rs b/servo/components/style/properties/longhands/box.mako.rs
index 017bef38eaaf..783df43b744e 100644
--- a/servo/components/style/properties/longhands/box.mako.rs
+++ b/servo/components/style/properties/longhands/box.mako.rs
@@ -13,7 +13,7 @@ ${helpers.predefined_type(
     "display",
     "Display",
     "computed::Display::inline()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::Display::inline()",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-display/#propdef-display",
@@ -38,7 +38,7 @@ ${helpers.single_keyword(
 ${helpers.single_keyword(
     "-servo-top-layer",
     "none top",
-    engines="servo-2013 servo-2020",
+    engines="servo",
     animation_value_type="none",
     enabled_in="ua",
     spec="Internal (not web-exposed)",
@@ -47,8 +47,8 @@ ${helpers.single_keyword(
 
 <%helpers:single_keyword
     name="position"
-    values="static absolute relative fixed ${'sticky' if engine in ['gecko', 'servo-2013'] else ''}"
-    engines="gecko servo-2013 servo-2020"
+    values="static absolute relative fixed sticky"
+    engines="gecko servo"
     animation_value_type="discrete"
     gecko_enum_prefix="StylePositionProperty"
     spec="https://drafts.csswg.org/css-position/#position-property"
@@ -69,8 +69,7 @@ ${helpers.predefined_type(
     "float",
     "Float",
     "computed::Float::None",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
     initial_specified_value="specified::Float::None",
     spec="https://drafts.csswg.org/css-box/#propdef-float",
     animation_value_type="discrete",
@@ -83,7 +82,7 @@ ${helpers.predefined_type(
     "clear",
     "Clear",
     "computed::Clear::None",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css2/#propdef-clear",
     servo_restyle_damage="rebuild_and_reflow",
@@ -94,7 +93,7 @@ ${helpers.predefined_type(
     "vertical-align",
     "VerticalAlign",
     "computed::VerticalAlign::baseline()",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     spec="https://www.w3.org/TR/CSS2/visudet.html#propdef-vertical-align",
     servo_restyle_damage = "reflow",
@@ -105,7 +104,7 @@ ${helpers.predefined_type(
     "baseline-source",
     "BaselineSource",
     "computed::BaselineSource::Auto",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-inline-3/#baseline-source",
     servo_restyle_damage = "reflow",
@@ -117,7 +116,8 @@ ${helpers.predefined_type(
 ${helpers.single_keyword(
     "-servo-overflow-clip-box",
     "padding-box content-box",
-    engines="servo-2013",
+    engines="servo",
+    servo_pref="layout.legacy_layout",
     animation_value_type="none",
     enabled_in="ua",
     spec="Internal, not web-exposed, \
@@ -146,7 +146,7 @@ ${helpers.single_keyword(
         full_name,
         "Overflow",
         "computed::Overflow::Visible",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         logical_group="overflow",
         logical=logical,
         animation_value_type="discrete",
@@ -174,7 +174,7 @@ ${helpers.predefined_type(
     "transform",
     "Transform",
     "generics::transform::Transform::none()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     extra_prefixes=transform_extra_prefixes,
     animation_value_type="ComputedValue",
     flags="CAN_ANIMATE_ON_COMPOSITOR",
@@ -187,7 +187,7 @@ ${helpers.predefined_type(
     "rotate",
     "Rotate",
     "generics::transform::Rotate::None",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     boxed=True,
     flags="CAN_ANIMATE_ON_COMPOSITOR",
@@ -201,7 +201,7 @@ ${helpers.predefined_type(
     "scale",
     "Scale",
     "generics::transform::Scale::None",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     boxed=True,
     flags="CAN_ANIMATE_ON_COMPOSITOR",
@@ -215,7 +215,7 @@ ${helpers.predefined_type(
     "translate",
     "Translate",
     "generics::transform::Translate::None",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     boxed=True,
     flags="CAN_ANIMATE_ON_COMPOSITOR",
@@ -409,7 +409,7 @@ ${helpers.predefined_type(
     "perspective",
     "Perspective",
     "computed::Perspective::none()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     gecko_ffi_name="mChildPerspective",
     spec="https://drafts.csswg.org/css-transforms/#perspective",
     extra_prefixes=transform_extra_prefixes,
@@ -422,7 +422,7 @@ ${helpers.predefined_type(
     "perspective-origin",
     "Position",
     "computed::position::Position::center()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     boxed=True,
     extra_prefixes=transform_extra_prefixes,
     spec="https://drafts.csswg.org/css-transforms-2/#perspective-origin-property",
@@ -434,7 +434,7 @@ ${helpers.predefined_type(
 ${helpers.single_keyword(
     "backface-visibility",
     "visible hidden",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     gecko_enum_prefix="StyleBackfaceVisibility",
     spec="https://drafts.csswg.org/css-transforms/#backface-visibility-property",
     extra_prefixes=transform_extra_prefixes,
@@ -456,7 +456,7 @@ ${helpers.predefined_type(
     "transform-style",
     "TransformStyle",
     "computed::TransformStyle::Flat",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-transforms-2/#transform-style-property",
     extra_prefixes=transform_extra_prefixes,
     animation_value_type="discrete",
@@ -468,7 +468,7 @@ ${helpers.predefined_type(
     "transform-origin",
     "TransformOrigin",
     "computed::TransformOrigin::initial_value()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     extra_prefixes=transform_extra_prefixes,
     gecko_ffi_name="mTransformOrigin",
@@ -503,10 +503,11 @@ ${helpers.predefined_type(
     "container-type",
     "ContainerType",
     "computed::ContainerType::Normal",
-    engines="gecko",
+    engines="gecko servo",
     animation_value_type="none",
     enabled_in="ua",
     gecko_pref="layout.css.container-queries.enabled",
+    servo_pref="layout.container-queries.enabled",
     spec="https://drafts.csswg.org/css-contain-3/#container-type",
     affects="layout",
 )}
@@ -515,10 +516,11 @@ ${helpers.predefined_type(
     "container-name",
     "ContainerName",
     "computed::ContainerName::none()",
-    engines="gecko",
+    engines="gecko servo",
     animation_value_type="none",
     enabled_in="ua",
     gecko_pref="layout.css.container-queries.enabled",
+    servo_pref="layout.container-queries.enabled",
     spec="https://drafts.csswg.org/css-contain-3/#container-name",
     affects="",
 )}
diff --git a/servo/components/style/properties/longhands/column.mako.rs b/servo/components/style/properties/longhands/column.mako.rs
index 38c32938c631..7b3897c418e3 100644
--- a/servo/components/style/properties/longhands/column.mako.rs
+++ b/servo/components/style/properties/longhands/column.mako.rs
@@ -10,11 +10,10 @@ ${helpers.predefined_type(
     "column-width",
     "length::NonNegativeLengthOrAuto",
     "computed::length::NonNegativeLengthOrAuto::auto()",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
     initial_specified_value="specified::length::NonNegativeLengthOrAuto::auto()",
     animation_value_type="NonNegativeLengthOrAuto",
-    servo_2013_pref="layout.columns.enabled",
+    servo_pref="layout.columns.enabled",
     spec="https://drafts.csswg.org/css-multicol/#propdef-column-width",
     servo_restyle_damage="rebuild_and_reflow",
     affects="layout",
@@ -24,10 +23,9 @@ ${helpers.predefined_type(
     "column-count",
     "ColumnCount",
     "computed::ColumnCount::auto()",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
     initial_specified_value="specified::ColumnCount::auto()",
-    servo_2013_pref="layout.columns.enabled",
+    servo_pref="layout.columns.enabled",
     animation_value_type="AnimatedColumnCount",
     spec="https://drafts.csswg.org/css-multicol/#propdef-column-count",
     servo_restyle_damage="rebuild_and_reflow",
@@ -71,7 +69,8 @@ ${helpers.predefined_type(
 ${helpers.single_keyword(
     "column-span",
     "none all",
-    engines="gecko",
+    engines="gecko servo",
+    servo_pref="layout.columns.enabled",
     animation_value_type="discrete",
     gecko_enum_prefix="StyleColumnSpan",
     spec="https://drafts.csswg.org/css-multicol/#propdef-column-span",
diff --git a/servo/components/style/properties/longhands/counters.mako.rs b/servo/components/style/properties/longhands/counters.mako.rs
index 6c844c3567a9..363f96f89a71 100644
--- a/servo/components/style/properties/longhands/counters.mako.rs
+++ b/servo/components/style/properties/longhands/counters.mako.rs
@@ -10,7 +10,7 @@ ${helpers.predefined_type(
     "content",
     "Content",
     "computed::Content::normal()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::Content::normal()",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-content/#propdef-content",
@@ -21,7 +21,8 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "counter-increment",
     "CounterIncrement",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     initial_value="Default::default()",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-lists/#propdef-counter-increment",
@@ -32,7 +33,8 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "counter-reset",
     "CounterReset",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     initial_value="Default::default()",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-lists-3/#propdef-counter-reset",
diff --git a/servo/components/style/properties/longhands/effects.mako.rs b/servo/components/style/properties/longhands/effects.mako.rs
index b301aab5dd49..6c7b5c7eb2d1 100644
--- a/servo/components/style/properties/longhands/effects.mako.rs
+++ b/servo/components/style/properties/longhands/effects.mako.rs
@@ -11,7 +11,7 @@ ${helpers.predefined_type(
     "opacity",
     "Opacity",
     "1.0",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     flags="CAN_ANIMATE_ON_COMPOSITOR",
     spec="https://drafts.csswg.org/css-color/#transparency",
@@ -23,8 +23,8 @@ ${helpers.predefined_type(
     "box-shadow",
     "BoxShadow",
     None,
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     vector=True,
     simple_vector_bindings=True,
     animation_value_type="AnimatedBoxShadowList",
@@ -39,7 +39,7 @@ ${helpers.predefined_type(
     "clip",
     "ClipRectOrAuto",
     "computed::ClipRectOrAuto::auto()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     boxed=True,
     allow_quirks="Yes",
@@ -51,7 +51,7 @@ ${helpers.predefined_type(
     "filter",
     "Filter",
     None,
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     vector=True,
     simple_vector_bindings=True,
     gecko_ffi_name="mFilters",
@@ -84,7 +84,7 @@ ${helpers.single_keyword(
     """normal multiply screen overlay darken lighten color-dodge
     color-burn hard-light soft-light difference exclusion hue
     saturation color luminosity plus-lighter""",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     gecko_enum_prefix="StyleBlend",
     animation_value_type="discrete",
     spec="https://drafts.fxtf.org/compositing/#propdef-mix-blend-mode",
diff --git a/servo/components/style/properties/longhands/font.mako.rs b/servo/components/style/properties/longhands/font.mako.rs
index 4583de0bd740..67c633dc718e 100644
--- a/servo/components/style/properties/longhands/font.mako.rs
+++ b/servo/components/style/properties/longhands/font.mako.rs
@@ -10,7 +10,7 @@
 ${helpers.predefined_type(
     "font-family",
     "FontFamily",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::FontFamily::serif()",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-fonts/#propdef-font-family",
@@ -21,7 +21,7 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "font-style",
     "FontStyle",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::FontStyle::normal()",
     initial_specified_value="specified::FontStyle::normal()",
     animation_value_type="FontStyle",
@@ -39,7 +39,7 @@ ${helpers.predefined_type(
 ${helpers.single_keyword(
     "font-variant-caps",
     "normal small-caps",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     extra_gecko_values="all-small-caps petite-caps all-petite-caps unicase titling-caps",
     gecko_constant_prefix="NS_FONT_VARIANT_CAPS",
     gecko_ffi_name="mFont.variantCaps",
@@ -53,7 +53,7 @@ ${helpers.single_keyword(
 ${helpers.predefined_type(
     "font-weight",
     "FontWeight",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::FontWeight::normal()",
     initial_specified_value="specified::FontWeight::normal()",
     animation_value_type="Number",
@@ -65,7 +65,7 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "font-size",
     "FontSize",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::FontSize::medium()",
     initial_specified_value="specified::FontSize::medium()",
     animation_value_type="NonNegativeLength",
@@ -137,7 +137,7 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "font-stretch",
     "FontStretch",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::FontStretch::hundred()",
     initial_specified_value="specified::FontStretch::normal()",
     animation_value_type="Percentage",
@@ -354,7 +354,7 @@ ${helpers.predefined_type(
     "line-height",
     "LineHeight",
     "computed::LineHeight::normal()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     animation_value_type="LineHeight",
     spec="https://drafts.csswg.org/css2/visudet.html#propdef-line-height",
     servo_restyle_damage="reflow",
diff --git a/servo/components/style/properties/longhands/inherited_box.mako.rs b/servo/components/style/properties/longhands/inherited_box.mako.rs
index 7fd94d1a1f8b..0fa6fa7c14a0 100644
--- a/servo/components/style/properties/longhands/inherited_box.mako.rs
+++ b/servo/components/style/properties/longhands/inherited_box.mako.rs
@@ -10,7 +10,7 @@
 ${helpers.single_keyword(
     "visibility",
     "visible hidden collapse",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     gecko_ffi_name="mVisible",
     animation_value_type="ComputedValue",
     spec="https://drafts.csswg.org/css-box/#propdef-visibility",
@@ -23,13 +23,12 @@ ${helpers.single_keyword(
 ${helpers.single_keyword(
     "writing-mode",
     "horizontal-tb vertical-rl vertical-lr",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     extra_gecko_values="sideways-rl sideways-lr",
     gecko_aliases="lr=horizontal-tb lr-tb=horizontal-tb \
                          rl=horizontal-tb rl-tb=horizontal-tb \
                          tb=vertical-rl   tb-rl=vertical-rl",
-    servo_2013_pref="layout.writing-mode.enabled",
-    servo_2020_pref="layout.writing-mode.enabled",
+    servo_pref="layout.writing-mode.enabled",
     animation_value_type="none",
     spec="https://drafts.csswg.org/css-writing-modes/#propdef-writing-mode",
     gecko_enum_prefix="StyleWritingModeProperty",
@@ -40,8 +39,8 @@ ${helpers.single_keyword(
 ${helpers.single_keyword(
     "direction",
     "ltr rtl",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     animation_value_type="none",
     spec="https://drafts.csswg.org/css-writing-modes/#propdef-direction",
     gecko_enum_prefix="StyleDirection",
@@ -88,7 +87,7 @@ ${helpers.predefined_type(
     "image-rendering",
     "ImageRendering",
     "computed::ImageRendering::Auto",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-images/#propdef-image-rendering",
     animation_value_type="discrete",
     affects="paint",
diff --git a/servo/components/style/properties/longhands/inherited_table.mako.rs b/servo/components/style/properties/longhands/inherited_table.mako.rs
index 7eb42a6eb252..90db9d95d11c 100644
--- a/servo/components/style/properties/longhands/inherited_table.mako.rs
+++ b/servo/components/style/properties/longhands/inherited_table.mako.rs
@@ -9,7 +9,8 @@
 ${helpers.single_keyword(
     "border-collapse",
     "separate collapse",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     gecko_enum_prefix="StyleBorderCollapse",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-tables/#propdef-border-collapse",
@@ -20,7 +21,8 @@ ${helpers.single_keyword(
 ${helpers.single_keyword(
     "empty-cells",
     "show hide",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     gecko_enum_prefix="StyleEmptyCells",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-tables/#propdef-empty-cells",
@@ -32,7 +34,8 @@ ${helpers.predefined_type(
     "caption-side",
     "table::CaptionSide",
     "computed::table::CaptionSide::Top",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-tables/#propdef-caption-side",
     servo_restyle_damage="rebuild_and_reflow",
@@ -43,8 +46,7 @@ ${helpers.predefined_type(
     "border-spacing",
     "BorderSpacing",
     "computed::BorderSpacing::zero()",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
     animation_value_type="BorderSpacing",
     boxed=True,
     spec="https://drafts.csswg.org/css-tables/#propdef-border-spacing",
diff --git a/servo/components/style/properties/longhands/inherited_text.mako.rs b/servo/components/style/properties/longhands/inherited_text.mako.rs
index 544ba99bf7c4..04f2bbed81da 100644
--- a/servo/components/style/properties/longhands/inherited_text.mako.rs
+++ b/servo/components/style/properties/longhands/inherited_text.mako.rs
@@ -10,7 +10,7 @@ ${helpers.predefined_type(
     "color",
     "ColorPropertyValue",
     "crate::color::AbsoluteColor::BLACK",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     animation_value_type="AbsoluteColor",
     ignored_when_colors_disabled="True",
     spec="https://drafts.csswg.org/css-color/#color",
@@ -23,7 +23,8 @@ ${helpers.predefined_type(
     "text-transform",
     "TextTransform",
     "computed::TextTransform::none()",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text/#propdef-text-transform",
     servo_restyle_damage="rebuild_and_reflow",
@@ -58,8 +59,7 @@ ${helpers.predefined_type(
     "text-indent",
     "TextIndent",
     "computed::TextIndent::zero()",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     spec="https://drafts.csswg.org/css-text/#propdef-text-indent",
     servo_restyle_damage = "reflow",
@@ -72,8 +72,8 @@ ${helpers.predefined_type(
     "overflow-wrap",
     "OverflowWrap",
     "computed::OverflowWrap::Normal",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text/#propdef-overflow-wrap",
     aliases="word-wrap",
@@ -85,8 +85,8 @@ ${helpers.predefined_type(
     "word-break",
     "WordBreak",
     "computed::WordBreak::Normal",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text/#propdef-word-break",
     servo_restyle_damage="rebuild_and_reflow",
@@ -97,8 +97,7 @@ ${helpers.predefined_type(
     "text-justify",
     "TextJustify",
     "computed::TextJustify::Auto",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text/#propdef-text-justify",
     servo_restyle_damage="rebuild_and_reflow",
@@ -109,7 +108,7 @@ ${helpers.predefined_type(
     "text-align-last",
     "TextAlignLast",
     "computed::text::TextAlignLast::Auto",
-    engines="gecko",
+    engines="gecko servo",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text/#propdef-text-align-last",
     affects="layout",
@@ -120,7 +119,7 @@ ${helpers.predefined_type(
     "text-align",
     "TextAlign",
     "computed::TextAlign::Start",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text/#propdef-text-align",
     servo_restyle_damage = "reflow",
@@ -131,7 +130,7 @@ ${helpers.predefined_type(
     "letter-spacing",
     "LetterSpacing",
     "computed::LetterSpacing::normal()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     spec="https://drafts.csswg.org/css-text/#propdef-letter-spacing",
     servo_restyle_damage="rebuild_and_reflow",
@@ -142,7 +141,7 @@ ${helpers.predefined_type(
     "word-spacing",
     "WordSpacing",
     "computed::WordSpacing::zero()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     spec="https://drafts.csswg.org/css-text/#propdef-word-spacing",
     servo_restyle_damage="rebuild_and_reflow",
@@ -164,7 +163,8 @@ ${helpers.predefined_type(
     "text-shadow",
     "SimpleShadow",
     None,
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     vector=True,
     vector_animation_type="with_zero",
     animation_value_type="AnimatedTextShadowList",
@@ -304,7 +304,7 @@ ${helpers.single_keyword(
 ${helpers.single_keyword(
     "text-rendering",
     "auto optimizespeed optimizelegibility geometricprecision",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     gecko_enum_prefix="StyleTextRendering",
     animation_value_type="discrete",
     spec="https://svgwg.org/svg2-draft/painting.html#TextRenderingProperty",
diff --git a/servo/components/style/properties/longhands/inherited_ui.mako.rs b/servo/components/style/properties/longhands/inherited_ui.mako.rs
index 6cdf721336f3..784c8e877fa1 100644
--- a/servo/components/style/properties/longhands/inherited_ui.mako.rs
+++ b/servo/components/style/properties/longhands/inherited_ui.mako.rs
@@ -10,7 +10,7 @@ ${helpers.predefined_type(
     "cursor",
     "Cursor",
     "computed::Cursor::auto()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::Cursor::auto()",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-ui/#cursor",
@@ -23,7 +23,7 @@ ${helpers.predefined_type(
 ${helpers.single_keyword(
     "pointer-events",
     "auto none",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     animation_value_type="discrete",
     extra_gecko_values="visiblepainted visiblefill visiblestroke visible painted fill stroke all",
     spec="https://svgwg.org/svg2-draft/interact.html#PointerEventsProperty",
diff --git a/servo/components/style/properties/longhands/list.mako.rs b/servo/components/style/properties/longhands/list.mako.rs
index 619724bd3202..00f2d5f7dbda 100644
--- a/servo/components/style/properties/longhands/list.mako.rs
+++ b/servo/components/style/properties/longhands/list.mako.rs
@@ -9,8 +9,8 @@
 ${helpers.single_keyword(
     "list-style-position",
     "outside inside",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     gecko_enum_prefix="StyleListStylePosition",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-lists/#propdef-list-style-position",
@@ -24,17 +24,16 @@ ${helpers.single_keyword(
 //     upper-roman
 //
 // [1]: http://dev.w3.org/csswg/css-counter-styles/
-% if engine in ["servo-2013", "servo-2020"]:
+% if engine == "servo":
     ${helpers.single_keyword(
         "list-style-type",
-        "disc none circle square disclosure-open disclosure-closed",
-        extra_servo_2013_values="""
+        """disc none circle square disclosure-open disclosure-closed
             decimal lower-alpha upper-alpha arabic-indic bengali cambodian cjk-decimal devanagari
             gujarati gurmukhi kannada khmer lao malayalam mongolian myanmar oriya persian telugu
             thai tibetan cjk-earthly-branch cjk-heavenly-stem lower-greek hiragana hiragana-iroha
             katakana katakana-iroha
         """,
-        engines="servo-2013 servo-2020",
+        engines="servo",
         animation_value_type="discrete",
         spec="https://drafts.csswg.org/css-lists/#propdef-list-style-type",
         servo_restyle_damage="rebuild_and_reflow",
@@ -59,11 +58,12 @@ ${helpers.single_keyword(
 ${helpers.predefined_type(
     "list-style-image",
     "Image",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_value="computed::Image::None",
     initial_specified_value="specified::Image::None",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-lists/#propdef-list-style-image",
+    boxed=engine == "servo",
     servo_restyle_damage="rebuild_and_reflow",
     affects="layout",
 )}
@@ -72,7 +72,8 @@ ${helpers.predefined_type(
     "quotes",
     "Quotes",
     "computed::Quotes::get_initial_value()",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-content/#propdef-quotes",
     servo_restyle_damage="rebuild_and_reflow",
diff --git a/servo/components/style/properties/longhands/margin.mako.rs b/servo/components/style/properties/longhands/margin.mako.rs
index b5a87f968359..e20e0911e10b 100644
--- a/servo/components/style/properties/longhands/margin.mako.rs
+++ b/servo/components/style/properties/longhands/margin.mako.rs
@@ -16,7 +16,7 @@
         "margin-%s" % side[0],
         "LengthPercentageOrAuto",
         "computed::LengthPercentageOrAuto::zero()",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         aliases=maybe_moz_logical_alias(engine, side, "-moz-margin-%s"),
         allow_quirks="No" if side[1] else "Yes",
         animation_value_type="ComputedValue",
diff --git a/servo/components/style/properties/longhands/outline.mako.rs b/servo/components/style/properties/longhands/outline.mako.rs
index 8e7f956bf52e..a1f49d8f8faf 100644
--- a/servo/components/style/properties/longhands/outline.mako.rs
+++ b/servo/components/style/properties/longhands/outline.mako.rs
@@ -14,7 +14,7 @@ ${helpers.predefined_type(
     "outline-color",
     "Color",
     "computed_value::T::currentcolor()",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     initial_specified_value="specified::Color::currentcolor()",
     animation_value_type="AnimatedColor",
     ignored_when_colors_disabled=True,
@@ -26,8 +26,7 @@ ${helpers.predefined_type(
     "outline-style",
     "OutlineStyle",
     "computed::OutlineStyle::none()",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
     initial_specified_value="specified::OutlineStyle::none()",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-ui/#propdef-outline-style",
@@ -38,8 +37,7 @@ ${helpers.predefined_type(
     "outline-width",
     "BorderSideWidth",
     "app_units::Au::from_px(3)",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.2020.unimplemented",
+    engines="gecko servo",
     initial_specified_value="specified::BorderSideWidth::medium()",
     animation_value_type="NonNegativeLength",
     spec="https://drafts.csswg.org/css-ui/#propdef-outline-width",
@@ -50,7 +48,7 @@ ${helpers.predefined_type(
     "outline-offset",
     "Length",
     "crate::values::computed::Length::new(0.)",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     animation_value_type="ComputedValue",
     spec="https://drafts.csswg.org/css-ui/#propdef-outline-offset",
     affects="overflow",
diff --git a/servo/components/style/properties/longhands/padding.mako.rs b/servo/components/style/properties/longhands/padding.mako.rs
index a165e2cd342c..4c416c4fac93 100644
--- a/servo/components/style/properties/longhands/padding.mako.rs
+++ b/servo/components/style/properties/longhands/padding.mako.rs
@@ -16,7 +16,7 @@
         "padding-%s" % side[0],
         "NonNegativeLengthPercentage",
         "computed::NonNegativeLengthPercentage::zero()",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         aliases=maybe_moz_logical_alias(engine, side, "-moz-padding-%s"),
         animation_value_type="NonNegativeLengthPercentage",
         logical=side[1],
diff --git a/servo/components/style/properties/longhands/position.mako.rs b/servo/components/style/properties/longhands/position.mako.rs
index fb68baa6b466..6121d1668eb7 100644
--- a/servo/components/style/properties/longhands/position.mako.rs
+++ b/servo/components/style/properties/longhands/position.mako.rs
@@ -14,7 +14,7 @@
         side,
         "LengthPercentageOrAuto",
         "computed::LengthPercentageOrAuto::auto()",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         spec="https://www.w3.org/TR/CSS2/visuren.html#propdef-%s" % side,
         animation_value_type="ComputedValue",
         allow_quirks="Yes",
@@ -29,7 +29,7 @@
         "inset-%s" % side,
         "LengthPercentageOrAuto",
         "computed::LengthPercentageOrAuto::auto()",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         spec="https://drafts.csswg.org/css-logical-props/#propdef-inset-%s" % side,
         animation_value_type="ComputedValue",
         logical=True,
@@ -42,7 +42,7 @@ ${helpers.predefined_type(
     "z-index",
     "ZIndex",
     "computed::ZIndex::auto()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://www.w3.org/TR/CSS2/visuren.html#z-index",
     animation_value_type="ComputedValue",
     affects="paint",
@@ -55,8 +55,8 @@ ${helpers.predefined_type(
 ${helpers.single_keyword(
     "flex-direction",
     "row row-reverse column column-reverse",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.flexbox.enabled",
+    engines="gecko servo",
+    servo_pref="layout.flexbox.enabled",
     spec="https://drafts.csswg.org/css-flexbox/#flex-direction-property",
     extra_prefixes="webkit",
     animation_value_type="discrete",
@@ -68,8 +68,8 @@ ${helpers.single_keyword(
 ${helpers.single_keyword(
     "flex-wrap",
     "nowrap wrap wrap-reverse",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.flexbox.enabled",
+    engines="gecko servo",
+    servo_pref="layout.flexbox.enabled",
     spec="https://drafts.csswg.org/css-flexbox/#flex-wrap-property",
     extra_prefixes="webkit",
     animation_value_type="discrete",
@@ -78,12 +78,13 @@ ${helpers.single_keyword(
     affects="layout",
 )}
 
-% if engine == "servo-2013":
+% if engine in "servo":
     // FIXME: Update Servo to support the same Syntax as Gecko.
     ${helpers.single_keyword(
         "justify-content",
         "flex-start stretch flex-end center space-between space-around",
-        engines="servo-2013",
+        engines="servo",
+        servo_pref="layout.flexbox.enabled",
         extra_prefixes="webkit",
         spec="https://drafts.csswg.org/css-align/#propdef-justify-content",
         animation_value_type="discrete",
@@ -117,12 +118,13 @@ ${helpers.single_keyword(
     )}
 % endif
 
-% if engine in ["servo-2013", "servo-2020"]:
+% if engine == "servo":
     // FIXME: Update Servo to support the same Syntax as Gecko.
     ${helpers.single_keyword(
         "align-content",
         "stretch flex-start flex-end center space-between space-around",
-        engines="servo-2013",
+        engines="servo",
+        servo_pref="layout.flexbox.enabled",
         extra_prefixes="webkit",
         spec="https://drafts.csswg.org/css-align/#propdef-align-content",
         animation_value_type="discrete",
@@ -133,8 +135,8 @@ ${helpers.single_keyword(
     ${helpers.single_keyword(
         "align-items",
         "stretch flex-start flex-end center baseline",
-        engines="servo-2013 servo-2020",
-        servo_2020_pref="layout.flexbox.enabled",
+        engines="servo",
+        servo_pref="layout.flexbox.enabled",
         extra_prefixes="webkit",
         spec="https://drafts.csswg.org/css-flexbox/#align-items-property",
         animation_value_type="discrete",
@@ -195,8 +197,8 @@ ${helpers.predefined_type(
     "flex-grow",
     "NonNegativeNumber",
     "From::from(0.0)",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.flexbox.enabled",
+    engines="gecko servo",
+    servo_pref="layout.flexbox.enabled",
     spec="https://drafts.csswg.org/css-flexbox/#flex-grow-property",
     extra_prefixes="webkit",
     animation_value_type="NonNegativeNumber",
@@ -208,8 +210,8 @@ ${helpers.predefined_type(
     "flex-shrink",
     "NonNegativeNumber",
     "From::from(1.0)",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.flexbox.enabled",
+    engines="gecko servo",
+    servo_pref="layout.flexbox.enabled",
     spec="https://drafts.csswg.org/css-flexbox/#flex-shrink-property",
     extra_prefixes="webkit",
     animation_value_type="NonNegativeNumber",
@@ -218,13 +220,13 @@ ${helpers.predefined_type(
 )}
 
 // https://drafts.csswg.org/css-align/#align-self-property
-% if engine in ["servo-2013", "servo-2020"]:
+% if engine == "servo":
     // FIXME: Update Servo to support the same syntax as Gecko.
     ${helpers.single_keyword(
         "align-self",
         "auto stretch flex-start flex-end center baseline",
-        engines="servo-2013 servo-2020",
-        servo_2020_pref="layout.flexbox.enabled",
+        engines="servo",
+        servo_pref="layout.flexbox.enabled",
         extra_prefixes="webkit",
         spec="https://drafts.csswg.org/css-flexbox/#propdef-align-self",
         animation_value_type="discrete",
@@ -260,8 +262,8 @@ ${helpers.predefined_type(
     "order",
     "Integer",
     "0",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.flexbox.enabled",
+    engines="gecko servo",
+    servo_pref="layout.flexbox.enabled",
     extra_prefixes="webkit",
     animation_value_type="ComputedValue",
     spec="https://drafts.csswg.org/css-flexbox/#order-property",
@@ -273,8 +275,8 @@ ${helpers.predefined_type(
     "flex-basis",
     "FlexBasis",
     "computed::FlexBasis::auto()",
-    engines="gecko servo-2013 servo-2020",
-    servo_2020_pref="layout.flexbox.enabled",
+    engines="gecko servo",
+    servo_pref="layout.flexbox.enabled",
     spec="https://drafts.csswg.org/css-flexbox/#flex-basis-property",
     extra_prefixes="webkit",
     animation_value_type="FlexBasis",
@@ -294,7 +296,7 @@ ${helpers.predefined_type(
         size,
         "Size",
         "computed::Size::auto()",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         logical=logical,
         logical_group="size",
         allow_quirks="No" if logical else "Yes",
@@ -308,7 +310,7 @@ ${helpers.predefined_type(
         "min-%s" % size,
         "Size",
         "computed::Size::auto()",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         logical=logical,
         logical_group="min-size",
         allow_quirks="No" if logical else "Yes",
@@ -321,7 +323,7 @@ ${helpers.predefined_type(
         "max-%s" % size,
         "MaxSize",
         "computed::MaxSize::none()",
-        engines="gecko servo-2013 servo-2020",
+        engines="gecko servo",
         logical=logical,
         logical_group="max-size",
         allow_quirks="No" if logical else "Yes",
@@ -335,7 +337,7 @@ ${helpers.predefined_type(
 ${helpers.single_keyword(
     "box-sizing",
     "content-box border-box",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     extra_prefixes="moz:layout.css.prefixes.box-sizing webkit",
     spec="https://drafts.csswg.org/css-ui/#propdef-box-sizing",
     gecko_enum_prefix="StyleBoxSizing",
@@ -436,9 +438,9 @@ ${helpers.predefined_type(
     "column-gap",
     "length::NonNegativeLengthPercentageOrNormal",
     "computed::length::NonNegativeLengthPercentageOrNormal::normal()",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     aliases="grid-column-gap" if engine == "gecko" else "",
-    servo_2013_pref="layout.columns.enabled",
+    servo_pref="layout.columns.enabled",
     spec="https://drafts.csswg.org/css-align-3/#propdef-column-gap",
     animation_value_type="NonNegativeLengthPercentageOrNormal",
     servo_restyle_damage="reflow",
@@ -462,7 +464,8 @@ ${helpers.predefined_type(
     "aspect-ratio",
     "AspectRatio",
     "computed::AspectRatio::auto()",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     animation_value_type="ComputedValue",
     spec="https://drafts.csswg.org/css-sizing-4/#aspect-ratio",
     servo_restyle_damage="reflow",
diff --git a/servo/components/style/properties/longhands/table.mako.rs b/servo/components/style/properties/longhands/table.mako.rs
index 3a756636ada1..f80579c958af 100644
--- a/servo/components/style/properties/longhands/table.mako.rs
+++ b/servo/components/style/properties/longhands/table.mako.rs
@@ -9,7 +9,8 @@
 ${helpers.single_keyword(
     "table-layout",
     "auto fixed",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     gecko_ffi_name="mLayoutStrategy",
     animation_value_type="discrete",
     gecko_enum_prefix="StyleTableLayout",
diff --git a/servo/components/style/properties/longhands/text.mako.rs b/servo/components/style/properties/longhands/text.mako.rs
index 0ee8ba31685d..775848aa4613 100644
--- a/servo/components/style/properties/longhands/text.mako.rs
+++ b/servo/components/style/properties/longhands/text.mako.rs
@@ -11,7 +11,8 @@ ${helpers.predefined_type(
     "text-overflow",
     "TextOverflow",
     "computed::TextOverflow::get_initial_value()",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     animation_value_type="discrete",
     boxed=True,
     spec="https://drafts.csswg.org/css-ui/#propdef-text-overflow",
@@ -22,7 +23,8 @@ ${helpers.predefined_type(
 ${helpers.single_keyword(
     "unicode-bidi",
     "normal embed isolate bidi-override isolate-override plaintext",
-    engines="gecko servo-2013",
+    engines="gecko servo",
+    servo_pref="layout.legacy_layout",
     gecko_enum_prefix="StyleUnicodeBidi",
     animation_value_type="none",
     spec="https://drafts.csswg.org/css-writing-modes/#propdef-unicode-bidi",
@@ -34,7 +36,7 @@ ${helpers.predefined_type(
     "text-decoration-line",
     "TextDecorationLine",
     "specified::TextDecorationLine::none()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::TextDecorationLine::none()",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text-decor/#propdef-text-decoration-line",
@@ -45,7 +47,7 @@ ${helpers.predefined_type(
 ${helpers.single_keyword(
     "text-decoration-style",
     "solid double dotted dashed wavy -moz-none",
-    engines="gecko servo-2020",
+    engines="gecko servo",
     gecko_enum_prefix="StyleTextDecorationStyle",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text-decor/#propdef-text-decoration-style",
@@ -56,7 +58,7 @@ ${helpers.predefined_type(
     "text-decoration-color",
     "Color",
     "computed_value::T::currentcolor()",
-    engines="gecko servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::Color::currentcolor()",
     animation_value_type="AnimatedColor",
     ignored_when_colors_disabled=True,
diff --git a/servo/components/style/properties/longhands/ui.mako.rs b/servo/components/style/properties/longhands/ui.mako.rs
index 58006e0d6506..c687344d919a 100644
--- a/servo/components/style/properties/longhands/ui.mako.rs
+++ b/servo/components/style/properties/longhands/ui.mako.rs
@@ -145,7 +145,7 @@ ${helpers.predefined_type(
     "transition-duration",
     "Time",
     "computed::Time::zero()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::Time::zero()",
     parse_method="parse_non_negative",
     vector=True,
@@ -160,7 +160,7 @@ ${helpers.predefined_type(
     "transition-timing-function",
     "TimingFunction",
     "computed::TimingFunction::ease()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::TimingFunction::ease()",
     vector=True,
     need_index=True,
@@ -174,7 +174,7 @@ ${helpers.predefined_type(
     "transition-property",
     "TransitionProperty",
     "computed::TransitionProperty::all()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::TransitionProperty::all()",
     vector=True,
     none_value="computed::TransitionProperty::none()",
@@ -189,7 +189,7 @@ ${helpers.predefined_type(
     "transition-delay",
     "Time",
     "computed::Time::zero()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::Time::zero()",
     vector=True,
     need_index=True,
@@ -219,7 +219,7 @@ ${helpers.predefined_type(
     "animation-name",
     "AnimationName",
     "computed::AnimationName::none()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::AnimationName::none()",
     vector=True,
     need_index=True,
@@ -234,7 +234,7 @@ ${helpers.predefined_type(
     "animation-duration",
     "Time",
     "computed::Time::zero()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::Time::zero()",
     parse_method="parse_non_negative",
     vector=True,
@@ -251,7 +251,7 @@ ${helpers.predefined_type(
     "animation-timing-function",
     "TimingFunction",
     "computed::TimingFunction::ease()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::TimingFunction::ease()",
     vector=True,
     need_index=True,
@@ -265,7 +265,7 @@ ${helpers.predefined_type(
     "animation-iteration-count",
     "AnimationIterationCount",
     "computed::AnimationIterationCount::one()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::AnimationIterationCount::one()",
     vector=True,
     need_index=True,
@@ -280,7 +280,7 @@ ${helpers.predefined_type(
     "animation-direction",
     "AnimationDirection",
     "computed::AnimationDirection::Normal",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::AnimationDirection::Normal",
     vector=True,
     need_index=True,
@@ -295,7 +295,7 @@ ${helpers.predefined_type(
     "animation-play-state",
     "AnimationPlayState",
     "computed::AnimationPlayState::Running",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="computed::AnimationPlayState::Running",
     vector=True,
     need_index=True,
@@ -310,7 +310,7 @@ ${helpers.predefined_type(
     "animation-fill-mode",
     "AnimationFillMode",
     "computed::AnimationFillMode::None",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="computed::AnimationFillMode::None",
     vector=True,
     need_index=True,
@@ -325,12 +325,13 @@ ${helpers.predefined_type(
     "animation-composition",
     "AnimationComposition",
     "computed::AnimationComposition::Replace",
-    engines="gecko",
+    engines="gecko servo",
     initial_specified_value="computed::AnimationComposition::Replace",
     vector=True,
     need_index=True,
     animation_value_type="none",
     gecko_pref="layout.css.animation-composition.enabled",
+    servo_pref="layout.unimplemented",
     spec="https://drafts.csswg.org/css-animations-2/#animation-composition",
     affects="",
 )}
@@ -339,7 +340,7 @@ ${helpers.predefined_type(
     "animation-delay",
     "Time",
     "computed::Time::zero()",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     initial_specified_value="specified::Time::zero()",
     vector=True,
     need_index=True,
@@ -354,7 +355,8 @@ ${helpers.predefined_type(
     "animation-timeline",
     "AnimationTimeline",
     "computed::AnimationTimeline::auto()",
-    engines="gecko",
+    engines="gecko servo",
+    servo_pref="layout.unimplemented",
     initial_specified_value="specified::AnimationTimeline::auto()",
     vector=True,
     need_index=True,
diff --git a/servo/components/style/properties/properties.mako.rs b/servo/components/style/properties/properties.mako.rs
index b08314d7d5f0..23ee2b3671b6 100644
--- a/servo/components/style/properties/properties.mako.rs
+++ b/servo/components/style/properties/properties.mako.rs
@@ -142,7 +142,7 @@ pub mod shorthands {
         data.declare_shorthand(
             "all",
             logical_longhands + other_longhands,
-            engines="gecko servo-2013 servo-2020",
+            engines="gecko servo",
             spec="https://drafts.csswg.org/css-cascade-3/#all-shorthand"
         )
         ALL_SHORTHAND_LEN = len(logical_longhands) + len(other_longhands);
@@ -505,8 +505,7 @@ impl NonCustomPropertyId {
                 }] = [
                     % for property in data.longhands + data.shorthands + data.all_aliases():
                         <%
-                            attrs = {"servo-2013": "servo_2013_pref", "servo-2020": "servo_2020_pref"}
-                            pref = getattr(property, attrs[engine])
+                            pref = getattr(property, "servo_pref")
                         %>
                         % if pref:
                             Some("${pref}"),
@@ -2482,7 +2481,7 @@ impl<'a> StyleBuilder<'a> {
     }
     % endif
 
-    % if not property.is_vector or property.simple_vector_bindings or engine in ["servo-2013", "servo-2020"]:
+    % if not property.is_vector or property.simple_vector_bindings or engine == "servo":
     /// Set the `${property.ident}` to the computed value `value`.
     #[allow(non_snake_case)]
     pub fn set_${property.ident}(
@@ -2932,7 +2931,7 @@ const_assert!(std::mem::size_of::<longhands::${longhand.ident}::SpecifiedValue>(
 % endif
 % endfor
 
-% if engine in ["servo-2013", "servo-2020"]:
+% if engine == "servo":
 % for effect_name in ["repaint", "reflow_out_of_flow", "reflow", "rebuild_and_reflow_inline", "rebuild_and_reflow"]:
     macro_rules! restyle_damage_${effect_name} {
         ($old: ident, $new: ident, $damage: ident, [ $($effect:expr),* ]) => ({
diff --git a/servo/components/style/properties/shorthands/background.mako.rs b/servo/components/style/properties/shorthands/background.mako.rs
index 08838233f6d0..5fee5cb2b03d 100644
--- a/servo/components/style/properties/shorthands/background.mako.rs
+++ b/servo/components/style/properties/shorthands/background.mako.rs
@@ -6,7 +6,7 @@
 
 // TODO: other background-* properties
 <%helpers:shorthand name="background"
-                    engines="gecko servo-2013 servo-2020"
+                    engines="gecko servo"
                     sub_properties="background-color background-position-x background-position-y background-repeat
                                     background-attachment background-image background-size background-origin
                                     background-clip"
@@ -230,7 +230,7 @@
 </%helpers:shorthand>
 
 <%helpers:shorthand name="background-position"
-                    engines="gecko servo-2013 servo-2020"
+                    engines="gecko servo"
                     flags="SHORTHAND_IN_GETCS"
                     sub_properties="background-position-x background-position-y"
                     spec="https://drafts.csswg.org/css-backgrounds-4/#the-background-position">
diff --git a/servo/components/style/properties/shorthands/border.mako.rs b/servo/components/style/properties/shorthands/border.mako.rs
index c6a87f3197b6..2eeb691e242d 100644
--- a/servo/components/style/properties/shorthands/border.mako.rs
+++ b/servo/components/style/properties/shorthands/border.mako.rs
@@ -9,7 +9,7 @@ ${helpers.four_sides_shorthand(
     "border-color",
     "border-%s-color",
     "specified::Color::parse",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-backgrounds/#border-color",
     allow_quirks="Yes",
 )}
@@ -17,13 +17,13 @@ ${helpers.four_sides_shorthand(
 ${helpers.four_sides_shorthand(
     "border-style",
     "border-%s-style",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-backgrounds/#border-style",
 )}
 
 <%helpers:shorthand
     name="border-width"
-    engines="gecko servo-2013 servo-2020"
+    engines="gecko servo"
     sub_properties="${
         ' '.join('border-%s-width' % side
                  for side in PHYSICAL_SIDES)}"
@@ -104,7 +104,7 @@ pub fn parse_border<'i, 't>(
     %>
     <%helpers:shorthand
         name="border-${side}"
-        engines="gecko servo-2013 servo-2020"
+        engines="gecko servo"
         sub_properties="${' '.join(
             'border-%s-%s' % (side, prop)
             for prop in ['width', 'style', 'color']
@@ -139,7 +139,7 @@ pub fn parse_border<'i, 't>(
 % endfor
 
 <%helpers:shorthand name="border"
-    engines="gecko servo-2013 servo-2020"
+    engines="gecko servo"
     sub_properties="${' '.join('border-%s-%s' % (side, prop)
         for side in PHYSICAL_SIDES for prop in ['width', 'style', 'color']
         )}
@@ -232,7 +232,7 @@ pub fn parse_border<'i, 't>(
 
 <%helpers:shorthand
     name="border-radius"
-    engines="gecko servo-2013 servo-2020"
+    engines="gecko servo"
     sub_properties="${' '.join(
         'border-%s-radius' % (corner)
          for corner in ['top-left', 'top-right', 'bottom-right', 'bottom-left']
@@ -278,7 +278,8 @@ pub fn parse_border<'i, 't>(
 
 <%helpers:shorthand
     name="border-image"
-    engines="gecko servo-2013"
+    engines="gecko servo"
+    servo_pref="layout.legacy_layout",
     sub_properties="border-image-outset
         border-image-repeat border-image-slice border-image-source border-image-width"
     extra_prefixes="moz:layout.css.prefixes.border-image webkit"
@@ -402,7 +403,7 @@ pub fn parse_border<'i, 't>(
             spec = "https://drafts.csswg.org/css-logical/#propdef-border-%s-%s" % (axis, prop)
         %>
         <%helpers:shorthand
-            engines="gecko servo-2013 servo-2020"
+            engines="gecko servo"
             name="border-${axis}-${prop}"
             sub_properties="${' '.join(
                 'border-%s-%s-%s' % (axis, side, prop)
@@ -448,7 +449,7 @@ pub fn parse_border<'i, 't>(
     %>
     <%helpers:shorthand
         name="border-${axis}"
-        engines="gecko servo-2013 servo-2020"
+        engines="gecko servo"
         sub_properties="${' '.join(
             'border-%s-%s-width' % (axis, side)
             for side in ['start', 'end']
diff --git a/servo/components/style/properties/shorthands/box.mako.rs b/servo/components/style/properties/shorthands/box.mako.rs
index f644687dc081..a8866ceaaa63 100644
--- a/servo/components/style/properties/shorthands/box.mako.rs
+++ b/servo/components/style/properties/shorthands/box.mako.rs
@@ -8,7 +8,7 @@ ${helpers.two_properties_shorthand(
     "overflow",
     "overflow-x",
     "overflow-y",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     flags="SHORTHAND_IN_GETCS",
     spec="https://drafts.csswg.org/css-overflow/#propdef-overflow",
 )}
diff --git a/servo/components/style/properties/shorthands/column.mako.rs b/servo/components/style/properties/shorthands/column.mako.rs
index 3740775a7ee9..4cf9a8d78661 100644
--- a/servo/components/style/properties/shorthands/column.mako.rs
+++ b/servo/components/style/properties/shorthands/column.mako.rs
@@ -5,9 +5,9 @@
 <%namespace name="helpers" file="/helpers.mako.rs" />
 
 <%helpers:shorthand name="columns"
-                    engines="gecko servo-2013"
+                    engines="gecko servo"
                     sub_properties="column-width column-count"
-                    servo_2013_pref="layout.columns.enabled",
+                    servo_pref="layout.columns.enabled"
                     spec="https://drafts.csswg.org/css-multicol/#propdef-columns">
     use crate::properties::longhands::{column_count, column_width};
 
diff --git a/servo/components/style/properties/shorthands/font.mako.rs b/servo/components/style/properties/shorthands/font.mako.rs
index 17dcf9d9267a..aaf0895aa5e8 100644
--- a/servo/components/style/properties/shorthands/font.mako.rs
+++ b/servo/components/style/properties/shorthands/font.mako.rs
@@ -7,7 +7,7 @@
 
 <%helpers:shorthand
     name="font"
-    engines="gecko servo-2013 servo-2020"
+    engines="gecko servo"
     sub_properties="
         font-style
         font-variant-caps
@@ -321,7 +321,8 @@
 </%helpers:shorthand>
 
 <%helpers:shorthand name="font-variant"
-                    engines="gecko servo-2013"
+                    engines="gecko servo"
+                    servo_pref="layout.legacy_layout",
                     flags="SHORTHAND_IN_GETCS"
                     sub_properties="font-variant-caps
                                     ${'font-variant-alternates' if engine == 'gecko' else ''}
diff --git a/servo/components/style/properties/shorthands/list.mako.rs b/servo/components/style/properties/shorthands/list.mako.rs
index 2e234e3d8ff6..183c5ab5daae 100644
--- a/servo/components/style/properties/shorthands/list.mako.rs
+++ b/servo/components/style/properties/shorthands/list.mako.rs
@@ -5,7 +5,7 @@
 <%namespace name="helpers" file="/helpers.mako.rs" />
 
 <%helpers:shorthand name="list-style"
-                    engines="gecko servo-2013 servo-2020"
+                    engines="gecko servo"
                     sub_properties="list-style-position list-style-image list-style-type"
                     spec="https://drafts.csswg.org/css-lists/#propdef-list-style">
     use crate::properties::longhands::{list_style_image, list_style_position, list_style_type};
@@ -110,7 +110,11 @@
             use longhands::list_style_type::SpecifiedValue as ListStyleType;
             use longhands::list_style_image::SpecifiedValue as ListStyleImage;
             let mut have_one_non_initial_value = false;
-            if self.list_style_position != &ListStylePosition::Outside {
+            #[cfg(feature = "gecko")]
+            let position_is_initial = self.list_style_position == &ListStylePosition::Outside;
+            #[cfg(feature = "servo")]
+            let position_is_initial = matches!(self.list_style_position, None | Some(&ListStylePosition::Outside));
+            if !position_is_initial {
                 self.list_style_position.to_css(dest)?;
                 have_one_non_initial_value = true;
             }
@@ -121,7 +125,11 @@
                 self.list_style_image.to_css(dest)?;
                 have_one_non_initial_value = true;
             }
-            if self.list_style_type != &ListStyleType::disc() {
+            #[cfg(feature = "gecko")]
+            let type_is_initial = self.list_style_type == &ListStyleType::disc();
+            #[cfg(feature = "servo")]
+            let type_is_initial = self.list_style_type == &ListStyleType::Disc;
+            if !type_is_initial {
                 if have_one_non_initial_value {
                     dest.write_char(' ')?;
                 }
@@ -129,7 +137,14 @@
                 have_one_non_initial_value = true;
             }
             if !have_one_non_initial_value {
+                #[cfg(feature = "gecko")]
                 self.list_style_position.to_css(dest)?;
+                #[cfg(feature = "servo")]
+                if let Some(position) = self.list_style_position {
+                    position.to_css(dest)?;
+                } else {
+                    self.list_style_type.to_css(dest)?;
+                }
             }
             Ok(())
         }
diff --git a/servo/components/style/properties/shorthands/margin.mako.rs b/servo/components/style/properties/shorthands/margin.mako.rs
index 6b5bf7e467b2..ba994316a215 100644
--- a/servo/components/style/properties/shorthands/margin.mako.rs
+++ b/servo/components/style/properties/shorthands/margin.mako.rs
@@ -9,7 +9,7 @@ ${helpers.four_sides_shorthand(
     "margin",
     "margin-%s",
     "specified::LengthPercentageOrAuto::parse",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-box/#propdef-margin",
     rule_types_allowed=DEFAULT_RULES_AND_PAGE,
     allow_quirks="Yes",
@@ -20,7 +20,7 @@ ${helpers.two_properties_shorthand(
     "margin-block-start",
     "margin-block-end",
     "specified::LengthPercentageOrAuto::parse",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-logical/#propdef-margin-block"
 )}
 
@@ -29,7 +29,7 @@ ${helpers.two_properties_shorthand(
     "margin-inline-start",
     "margin-inline-end",
     "specified::LengthPercentageOrAuto::parse",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-logical/#propdef-margin-inline"
 )}
 
diff --git a/servo/components/style/properties/shorthands/outline.mako.rs b/servo/components/style/properties/shorthands/outline.mako.rs
index 6ee8ed22c9fd..ff77e1175e24 100644
--- a/servo/components/style/properties/shorthands/outline.mako.rs
+++ b/servo/components/style/properties/shorthands/outline.mako.rs
@@ -5,7 +5,7 @@
 <%namespace name="helpers" file="/helpers.mako.rs" />
 
 <%helpers:shorthand name="outline"
-                    engines="gecko servo-2013"
+                    engines="gecko servo"
                     sub_properties="outline-color outline-style outline-width"
                     spec="https://drafts.csswg.org/css-ui/#propdef-outline">
     use crate::properties::longhands::{outline_color, outline_width, outline_style};
diff --git a/servo/components/style/properties/shorthands/padding.mako.rs b/servo/components/style/properties/shorthands/padding.mako.rs
index 11ddfed3b119..dad0193708dd 100644
--- a/servo/components/style/properties/shorthands/padding.mako.rs
+++ b/servo/components/style/properties/shorthands/padding.mako.rs
@@ -8,7 +8,7 @@ ${helpers.four_sides_shorthand(
     "padding",
     "padding-%s",
     "specified::NonNegativeLengthPercentage::parse",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-box-3/#propdef-padding",
     allow_quirks="Yes",
 )}
@@ -18,7 +18,7 @@ ${helpers.two_properties_shorthand(
     "padding-block-start",
     "padding-block-end",
     "specified::NonNegativeLengthPercentage::parse",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-logical/#propdef-padding-block"
 )}
 
@@ -27,7 +27,7 @@ ${helpers.two_properties_shorthand(
     "padding-inline-start",
     "padding-inline-end",
     "specified::NonNegativeLengthPercentage::parse",
-    engines="gecko servo-2013 servo-2020",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-logical/#propdef-padding-inline"
 )}
 
diff --git a/servo/components/style/properties/shorthands/position.mako.rs b/servo/components/style/properties/shorthands/position.mako.rs
index ed7df5e27aae..ac09bb27d613 100644
--- a/servo/components/style/properties/shorthands/position.mako.rs
+++ b/servo/components/style/properties/shorthands/position.mako.rs
@@ -5,8 +5,8 @@
 <%namespace name="helpers" file="/helpers.mako.rs" />
 
 <%helpers:shorthand name="flex-flow"
-                    engines="gecko servo-2013 servo-2020",
-                    servo_2020_pref="layout.flexbox.enabled",
+                    engines="gecko servo",
+                    servo_pref="layout.flexbox.enabled",
                     sub_properties="flex-direction flex-wrap"
                     extra_prefixes="webkit"
                     spec="https://drafts.csswg.org/css-flexbox/#flex-flow-property">
@@ -60,8 +60,8 @@
 </%helpers:shorthand>
 
 <%helpers:shorthand name="flex"
-                    engines="gecko servo-2013 servo-2020",
-                    servo_2020_pref="layout.flexbox.enabled",
+                    engines="gecko servo",
+                    servo_pref="layout.flexbox.enabled",
                     sub_properties="flex-grow flex-shrink flex-basis"
                     extra_prefixes="webkit"
                     derive_serialize="True"
@@ -858,7 +858,7 @@ ${helpers.four_sides_shorthand(
     "inset",
     "%s",
     "specified::LengthPercentageOrAuto::parse",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-logical/#propdef-inset",
     allow_quirks="No",
 )}
@@ -868,7 +868,7 @@ ${helpers.two_properties_shorthand(
     "inset-block-start",
     "inset-block-end",
     "specified::LengthPercentageOrAuto::parse",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-logical/#propdef-inset-block"
 )}
 
@@ -877,7 +877,7 @@ ${helpers.two_properties_shorthand(
     "inset-inline-start",
     "inset-inline-end",
     "specified::LengthPercentageOrAuto::parse",
-    engines="gecko servo-2013",
+    engines="gecko servo",
     spec="https://drafts.csswg.org/css-logical/#propdef-inset-inline"
 )}
 
diff --git a/servo/components/style/properties/shorthands/text.mako.rs b/servo/components/style/properties/shorthands/text.mako.rs
index 5b071be2c4b8..a913f818755e 100644
--- a/servo/components/style/properties/shorthands/text.mako.rs
+++ b/servo/components/style/properties/shorthands/text.mako.rs
@@ -5,7 +5,7 @@
 <%namespace name="helpers" file="/helpers.mako.rs" />
 
 <%helpers:shorthand name="text-decoration"
-                    engines="gecko servo-2013 servo-2020"
+                    engines="gecko servo"
                     flags="SHORTHAND_IN_GETCS"
                     sub_properties="text-decoration-line
                     ${' text-decoration-style text-decoration-color text-decoration-thickness' if engine == 'gecko' else ''}"
diff --git a/servo/components/style/properties/shorthands/ui.mako.rs b/servo/components/style/properties/shorthands/ui.mako.rs
index 4a27d5e0030c..9765a10376a7 100644
--- a/servo/components/style/properties/shorthands/ui.mako.rs
+++ b/servo/components/style/properties/shorthands/ui.mako.rs
@@ -18,7 +18,7 @@ macro_rules! try_parse_one {
 }
 
 <%helpers:shorthand name="transition"
-                    engines="gecko servo-2013 servo-2020"
+                    engines="gecko servo"
                     extra_prefixes="moz:layout.css.prefixes.transitions webkit"
                     sub_properties="transition-property transition-duration
                                     transition-timing-function
@@ -204,7 +204,7 @@ macro_rules! try_parse_one {
 </%helpers:shorthand>
 
 <%helpers:shorthand name="animation"
-                    engines="gecko servo-2013 servo-2020"
+                    engines="gecko servo"
                     extra_prefixes="moz:layout.css.prefixes.animations webkit"
                     sub_properties="animation-name animation-duration
                                     animation-timing-function animation-delay
diff --git a/servo/components/style/style_adjuster.rs b/servo/components/style/style_adjuster.rs
index a993d79d6a83..78a631ec1477 100644
--- a/servo/components/style/style_adjuster.rs
+++ b/servo/components/style/style_adjuster.rs
@@ -294,11 +294,9 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
                 .add_flags(ComputedValueFlags::SELF_OR_ANCESTOR_HAS_SIZE_CONTAINER_TYPE);
         }
 
-        #[cfg(feature = "servo-layout-2013")]
-        {
-            if self.style.get_parent_column().is_multicol() {
-                self.style.add_flags(ComputedValueFlags::CAN_BE_FRAGMENTED);
-            }
+        #[cfg(feature = "servo")]
+        if self.style.get_parent_column().is_multicol() {
+            self.style.add_flags(ComputedValueFlags::CAN_BE_FRAGMENTED);
         }
     }
 
diff --git a/servo/components/style/traversal.rs b/servo/components/style/traversal.rs
index d63c3cb965e1..fa256d0f6032 100644
--- a/servo/components/style/traversal.rs
+++ b/servo/components/style/traversal.rs
@@ -688,7 +688,7 @@ where
     element.finish_restyle(context, data, new_styles, important_rules_changed)
 }
 
-#[cfg(feature = "servo-layout-2013")]
+#[cfg(feature = "servo")]
 fn notify_paint_worklet<E>(context: &StyleContext<E>, data: &ElementData)
 where
     E: TElement,
@@ -726,7 +726,7 @@ where
     }
 }
 
-#[cfg(not(feature = "servo-layout-2013"))]
+#[cfg(not(feature = "servo"))]
 fn notify_paint_worklet<E>(_context: &StyleContext<E>, _data: &ElementData)
 where
     E: TElement,
diff --git a/servo/components/style/values/generics/counters.rs b/servo/components/style/values/generics/counters.rs
index 1d4518c57bfb..3f23c74b3346 100644
--- a/servo/components/style/values/generics/counters.rs
+++ b/servo/components/style/values/generics/counters.rs
@@ -4,11 +4,10 @@
 
 //! Generic types for counters-related CSS values.
 
-#[cfg(feature = "servo-layout-2013")]
+#[cfg(feature = "servo")]
 use crate::computed_values::list_style_type::T as ListStyleType;
 #[cfg(feature = "gecko")]
 use crate::values::generics::CounterStyle;
-#[cfg(any(feature = "gecko", feature = "servo-layout-2020"))]
 use crate::values::specified::Attr;
 use crate::values::CustomIdent;
 use std::fmt::{self, Write};
@@ -186,13 +185,13 @@ pub struct GenericCounters<I>(
 );
 pub use self::GenericCounters as Counters;
 
-#[cfg(feature = "servo-layout-2013")]
+#[cfg(feature = "servo")]
 type CounterStyleType = ListStyleType;
 
 #[cfg(feature = "gecko")]
 type CounterStyleType = CounterStyle;
 
-#[cfg(feature = "servo-layout-2013")]
+#[cfg(feature = "servo")]
 #[inline]
 fn is_decimal(counter_type: &CounterStyleType) -> bool {
     *counter_type == ListStyleType::Decimal
@@ -254,11 +253,9 @@ pub enum GenericContentItem<I> {
     /// Literal string content.
     String(crate::OwnedStr),
     /// `counter(name, style)`.
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     #[css(comma, function)]
     Counter(CustomIdent, #[css(skip_if = "is_decimal")] CounterStyleType),
     /// `counters(name, separator, style)`.
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     #[css(comma, function)]
     Counters(
         CustomIdent,
@@ -266,16 +263,12 @@ pub enum GenericContentItem<I> {
         #[css(skip_if = "is_decimal")] CounterStyleType,
     ),
     /// `open-quote`.
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     OpenQuote,
     /// `close-quote`.
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     CloseQuote,
     /// `no-open-quote`.
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     NoOpenQuote,
     /// `no-close-quote`.
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     NoCloseQuote,
     /// `-moz-alt-content`.
     #[cfg(feature = "gecko")]
@@ -286,7 +279,6 @@ pub enum GenericContentItem<I> {
     #[cfg(feature = "gecko")]
     MozLabelContent,
     /// `attr([namespace? `|`]? ident)`
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2020"))]
     Attr(Attr),
     /// image-set(url) | url(url)
     Image(I),
diff --git a/servo/components/style/values/generics/image.rs b/servo/components/style/values/generics/image.rs
index 6fc0870e15ff..ca1c716052b6 100644
--- a/servo/components/style/values/generics/image.rs
+++ b/servo/components/style/values/generics/image.rs
@@ -41,7 +41,7 @@ pub enum GenericImage<G, ImageUrl, Color, Percentage, Resolution> {
 
     /// A paint worklet image.
     /// <https://drafts.css-houdini.org/css-paint-api/>
-    #[cfg(feature = "servo-layout-2013")]
+    #[cfg(feature = "servo")]
     PaintWorklet(PaintWorklet),
 
     /// A `<cross-fade()>` image. Storing this directly inside of
@@ -416,7 +416,7 @@ where
             Image::None => dest.write_str("none"),
             Image::Url(ref url) => url.to_css(dest),
             Image::Gradient(ref gradient) => gradient.to_css(dest),
-            #[cfg(feature = "servo-layout-2013")]
+            #[cfg(feature = "servo")]
             Image::PaintWorklet(ref paint_worklet) => paint_worklet.to_css(dest),
             #[cfg(feature = "gecko")]
             Image::Element(ref selector) => {
diff --git a/servo/components/style/values/specified/box.rs b/servo/components/style/values/specified/box.rs
index 8414591c2bd3..737565641a4d 100644
--- a/servo/components/style/values/specified/box.rs
+++ b/servo/components/style/values/specified/box.rs
@@ -19,12 +19,12 @@ use std::fmt::{self, Write};
 use style_traits::{CssWriter, KeywordsCollectFn, ParseError};
 use style_traits::{SpecifiedValueInfo, StyleParseErrorKind, ToCss};
 
-#[cfg(not(feature = "servo-layout-2020"))]
+#[cfg(not(feature = "servo"))]
 fn flexbox_enabled() -> bool {
     true
 }
 
-#[cfg(feature = "servo-layout-2020")]
+#[cfg(feature = "servo")]
 fn flexbox_enabled() -> bool {
     servo_config::prefs::pref_map()
         .get("layout.flexbox.enabled")
@@ -42,9 +42,7 @@ pub enum DisplayOutside {
     None = 0,
     Inline,
     Block,
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     TableCaption,
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     InternalTable,
     #[cfg(feature = "gecko")]
     InternalRuby,
@@ -55,28 +53,19 @@ pub enum DisplayOutside {
 #[repr(u8)]
 pub enum DisplayInside {
     None = 0,
-    #[cfg(any(feature = "servo-layout-2020", feature = "gecko"))]
     Contents,
     Flow,
     FlowRoot,
     Flex,
     #[cfg(feature = "gecko")]
     Grid,
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     Table,
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     TableRowGroup,
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     TableColumn,
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     TableColumnGroup,
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     TableHeaderGroup,
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     TableFooterGroup,
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     TableRow,
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     TableCell,
     #[cfg(feature = "gecko")]
     Ruby,
@@ -145,7 +134,6 @@ impl Display {
     /// ::new() inlined so cbindgen can use it
     pub const None: Self =
         Self(((DisplayOutside::None as u16) << Self::OUTSIDE_SHIFT) | DisplayInside::None as u16);
-    #[cfg(any(feature = "servo-layout-2020", feature = "gecko"))]
     pub const Contents: Self = Self(
         ((DisplayOutside::None as u16) << Self::OUTSIDE_SHIFT) | DisplayInside::Contents as u16,
     );
@@ -170,14 +158,11 @@ impl Display {
     #[cfg(feature = "gecko")]
     pub const InlineGrid: Self =
         Self(((DisplayOutside::Inline as u16) << Self::OUTSIDE_SHIFT) | DisplayInside::Grid as u16);
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     pub const Table: Self =
         Self(((DisplayOutside::Block as u16) << Self::OUTSIDE_SHIFT) | DisplayInside::Table as u16);
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     pub const InlineTable: Self = Self(
         ((DisplayOutside::Inline as u16) << Self::OUTSIDE_SHIFT) | DisplayInside::Table as u16,
     );
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     pub const TableCaption: Self = Self(
         ((DisplayOutside::TableCaption as u16) << Self::OUTSIDE_SHIFT) | DisplayInside::Flow as u16,
     );
@@ -195,37 +180,30 @@ impl Display {
 
     // Internal table boxes.
 
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     pub const TableRowGroup: Self = Self(
         ((DisplayOutside::InternalTable as u16) << Self::OUTSIDE_SHIFT) |
             DisplayInside::TableRowGroup as u16,
     );
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     pub const TableHeaderGroup: Self = Self(
         ((DisplayOutside::InternalTable as u16) << Self::OUTSIDE_SHIFT) |
             DisplayInside::TableHeaderGroup as u16,
     );
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     pub const TableFooterGroup: Self = Self(
         ((DisplayOutside::InternalTable as u16) << Self::OUTSIDE_SHIFT) |
             DisplayInside::TableFooterGroup as u16,
     );
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     pub const TableColumn: Self = Self(
         ((DisplayOutside::InternalTable as u16) << Self::OUTSIDE_SHIFT) |
             DisplayInside::TableColumn as u16,
     );
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     pub const TableColumnGroup: Self = Self(
         ((DisplayOutside::InternalTable as u16) << Self::OUTSIDE_SHIFT) |
             DisplayInside::TableColumnGroup as u16,
     );
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     pub const TableRow: Self = Self(
         ((DisplayOutside::InternalTable as u16) << Self::OUTSIDE_SHIFT) |
             DisplayInside::TableRow as u16,
     );
-    #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
     pub const TableCell: Self = Self(
         ((DisplayOutside::InternalTable as u16) << Self::OUTSIDE_SHIFT) |
             DisplayInside::TableCell as u16,
@@ -336,7 +314,6 @@ impl Display {
     pub fn is_atomic_inline_level(&self) -> bool {
         match *self {
             Display::InlineBlock | Display::InlineFlex => true,
-            #[cfg(any(feature = "servo-layout-2013"))]
             Display::InlineTable => true,
             _ => false,
         }
@@ -373,7 +350,6 @@ impl Display {
     ///
     /// Also used for :root style adjustments.
     pub fn equivalent_block_display(&self, _is_root_element: bool) -> Self {
-        #[cfg(any(feature = "servo-layout-2020", feature = "gecko"))]
         {
             // Special handling for `contents` and `list-item`s on the root element.
             if _is_root_element && (self.is_contents() || self.is_list_item()) {
@@ -392,7 +368,6 @@ impl Display {
                 Display::from3(DisplayOutside::Block, inside, self.is_list_item())
             },
             DisplayOutside::Block | DisplayOutside::None => *self,
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             _ => Display::Block,
         }
     }
@@ -419,7 +394,6 @@ impl Display {
     #[inline]
     pub fn is_contents(&self) -> bool {
         match *self {
-            #[cfg(any(feature = "servo-layout-2020", feature = "gecko"))]
             Display::Contents => true,
             _ => false,
         }
@@ -444,30 +418,20 @@ impl DisplayKeyword {
         use self::DisplayKeyword::*;
         Ok(try_match_ident_ignore_ascii_case! { input,
             "none" => Full(Display::None),
-            #[cfg(any(feature = "servo-layout-2020", feature = "gecko"))]
             "contents" => Full(Display::Contents),
             "inline-block" => Full(Display::InlineBlock),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             "inline-table" => Full(Display::InlineTable),
             "-webkit-flex" if flexbox_enabled() => Full(Display::Flex),
             "inline-flex" | "-webkit-inline-flex" if flexbox_enabled() => Full(Display::InlineFlex),
             #[cfg(feature = "gecko")]
             "inline-grid" => Full(Display::InlineGrid),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             "table-caption" => Full(Display::TableCaption),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             "table-row-group" => Full(Display::TableRowGroup),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             "table-header-group" => Full(Display::TableHeaderGroup),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             "table-footer-group" => Full(Display::TableFooterGroup),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             "table-column" => Full(Display::TableColumn),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             "table-column-group" => Full(Display::TableColumnGroup),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             "table-row" => Full(Display::TableRow),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             "table-cell" => Full(Display::TableCell),
             #[cfg(feature = "gecko")]
             "ruby-base" => Full(Display::RubyBase),
@@ -493,9 +457,7 @@ impl DisplayKeyword {
             /// https://drafts.csswg.org/css-display/#typedef-display-inside
             "flow" => Inside(DisplayInside::Flow),
             "flex" if flexbox_enabled() => Inside(DisplayInside::Flex),
-            #[cfg(any(feature = "servo-layout-2020", feature = "gecko"))]
             "flow-root" => Inside(DisplayInside::FlowRoot),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             "table" => Inside(DisplayInside::Table),
             #[cfg(feature = "gecko")]
             "grid" => Inside(DisplayInside::Grid),
@@ -517,13 +479,11 @@ impl ToCss for Display {
             Display::InlineBlock => dest.write_str("inline-block"),
             #[cfg(feature = "gecko")]
             Display::WebkitInlineBox => dest.write_str("-webkit-inline-box"),
-            #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
             Display::TableCaption => dest.write_str("table-caption"),
             _ => match (outside, inside) {
                 #[cfg(feature = "gecko")]
                 (DisplayOutside::Inline, DisplayInside::Grid) => dest.write_str("inline-grid"),
                 (DisplayOutside::Inline, DisplayInside::Flex) => dest.write_str("inline-flex"),
-                #[cfg(any(feature = "servo-layout-2013", feature = "gecko"))]
                 (DisplayOutside::Inline, DisplayInside::Table) => dest.write_str("inline-table"),
                 #[cfg(feature = "gecko")]
                 (DisplayOutside::Block, DisplayInside::Ruby) => dest.write_str("block ruby"),
diff --git a/servo/components/style/values/specified/counters.rs b/servo/components/style/values/specified/counters.rs
index 9d8261ce6c15..7760be91d78e 100644
--- a/servo/components/style/values/specified/counters.rs
+++ b/servo/components/style/values/specified/counters.rs
@@ -4,7 +4,7 @@
 
 //! Specified types for counter properties.
 
-#[cfg(feature = "servo-layout-2013")]
+#[cfg(feature = "servo")]
 use crate::computed_values::list_style_type::T as ListStyleType;
 use crate::parser::{Parse, ParserContext};
 use crate::values::generics::counters as generics;
@@ -12,12 +12,10 @@ use crate::values::generics::counters::CounterPair;
 #[cfg(feature = "gecko")]
 use crate::values::generics::CounterStyle;
 use crate::values::specified::image::Image;
-#[cfg(any(feature = "gecko", feature = "servo-layout-2020"))]
 use crate::values::specified::Attr;
 use crate::values::specified::Integer;
 use crate::values::CustomIdent;
 use cssparser::{Parser, Token};
-#[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
 use selectors::parser::SelectorParseErrorKind;
 use style_traits::{ParseError, StyleParseErrorKind};
 
@@ -151,7 +149,7 @@ pub type Content = generics::GenericContent<Image>;
 pub type ContentItem = generics::GenericContentItem<Image>;
 
 impl Content {
-    #[cfg(feature = "servo-layout-2013")]
+    #[cfg(feature = "servo")]
     fn parse_counter_style(_: &ParserContext, input: &mut Parser) -> ListStyleType {
         input
             .try_parse(|input| {
@@ -197,7 +195,6 @@ impl Parse for Content {
         let mut content = vec![];
         let mut has_alt_content = false;
         loop {
-            #[cfg(any(feature = "gecko", feature = "servo-layout-2020"))]
             {
                 if let Ok(image) = input.try_parse(|i| Image::parse_forbid_none(context, i)) {
                     content.push(generics::ContentItem::Image(image));
@@ -212,13 +209,11 @@ impl Parse for Content {
                 },
                 Ok(&Token::Function(ref name)) => {
                     let result = match_ignore_ascii_case! { &name,
-                        #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
                         "counter" => input.parse_nested_block(|input| {
                             let name = CustomIdent::parse(input, &[])?;
                             let style = Content::parse_counter_style(context, input);
                             Ok(generics::ContentItem::Counter(name, style))
                         }),
-                        #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
                         "counters" => input.parse_nested_block(|input| {
                             let name = CustomIdent::parse(input, &[])?;
                             input.expect_comma()?;
@@ -226,7 +221,6 @@ impl Parse for Content {
                             let style = Content::parse_counter_style(context, input);
                             Ok(generics::ContentItem::Counters(name, separator, style))
                         }),
-                        #[cfg(any(feature = "gecko", feature = "servo-layout-2020"))]
                         "attr" => input.parse_nested_block(|input| {
                             Ok(generics::ContentItem::Attr(Attr::parse_function(context, input)?))
                         }),
@@ -240,7 +234,6 @@ impl Parse for Content {
                     }?;
                     content.push(result);
                 },
-                #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
                 Ok(&Token::Ident(ref ident)) => {
                     content.push(match_ignore_ascii_case! { &ident,
                         "open-quote" => generics::ContentItem::OpenQuote,
diff --git a/servo/components/style/values/specified/image.rs b/servo/components/style/values/specified/image.rs
index 76bbbf85df5b..bedced1a270a 100644
--- a/servo/components/style/values/specified/image.rs
+++ b/servo/components/style/values/specified/image.rs
@@ -241,7 +241,7 @@ impl Image {
         let function = input.expect_function()?.clone();
         input.parse_nested_block(|input| {
             Ok(match_ignore_ascii_case! { &function,
-                #[cfg(feature = "servo-layout-2013")]
+                #[cfg(feature = "servo")]
                 "paint" => Self::PaintWorklet(PaintWorklet::parse_args(context, input)?),
                 "cross-fade" if cross_fade_enabled() => Self::CrossFade(Box::new(CrossFade::parse_args(context, input, cors_mode, flags)?)),
                 #[cfg(feature = "gecko")]
diff --git a/servo/components/style/values/specified/text.rs b/servo/components/style/values/specified/text.rs
index 0e70bd26ac70..e26a17ba27fe 100644
--- a/servo/components/style/values/specified/text.rs
+++ b/servo/components/style/values/specified/text.rs
@@ -454,7 +454,6 @@ pub enum TextAlignKeyword {
     Left,
     Right,
     Center,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     Justify,
     #[css(skip)]
     #[cfg(feature = "gecko")]
@@ -466,11 +465,11 @@ pub enum TextAlignKeyword {
     MozLeft,
     #[cfg(feature = "gecko")]
     MozRight,
-    #[cfg(feature = "servo-layout-2013")]
+    #[cfg(feature = "servo")]
     ServoCenter,
-    #[cfg(feature = "servo-layout-2013")]
+    #[cfg(feature = "servo")]
     ServoLeft,
-    #[cfg(feature = "servo-layout-2013")]
+    #[cfg(feature = "servo")]
     ServoRight,
 }