Bug 1840476 - [css-properties-values-api] Custom property registration plumbing. r=zrhoffman,firefox-style-system-reviewers,webidl,saschanaz

This implements script registration and some basic validity checks so
that we start keeping track of custom properties in the CascadeData and
in script.

Differential Revision: https://phabricator.services.mozilla.com/D182110

dom/webidl/CSS.webidl

@@ -28,3 +28,16 @@ partial namespace CSS {
   [Pref="dom.customHighlightAPI.enabled", GetterThrows]
   readonly attribute HighlightRegistry highlights;
 };
+
+// https://drafts.css-houdini.org/css-properties-values-api-1/#registering-custom-properties
+// See https://github.com/w3c/css-houdini-drafts/pull/1100 for DOMString vs. UTF8String
+dictionary PropertyDefinition {
+  required UTF8String name;
+           UTF8String syntax       = "*";
+  required boolean    inherits;
+           UTF8String initialValue;
+};
+partial namespace CSS {
+  [Pref="layout.css.properties-and-values.enabled", Throws]
+  undefined registerProperty(PropertyDefinition definition);
+};

layout/style/CSS.cpp

@@ -16,8 +16,7 @@
 #include "nsStyleUtil.h"
 #include "xpcpublic.h"
 
-namespace mozilla {
-namespace dom {
+namespace mozilla::dom {
 
 /* static */
 bool CSS::Supports(const GlobalObject&, const nsACString& aProperty,
@@ -37,27 +36,37 @@ void CSS::Escape(const GlobalObject&, const nsAString& aIdent,
   nsStyleUtil::AppendEscapedCSSIdent(aIdent, aReturn);
 }
 
+static Document* GetDocument(const GlobalObject& aGlobal) {
+  nsCOMPtr<nsPIDOMWindowInner> window =
+      do_QueryInterface(aGlobal.GetAsSupports());
+  MOZ_DIAGNOSTIC_ASSERT(window, "CSS is only exposed to window globals");
+  if (!window) {
+    return nullptr;
+  }
+  return window->GetExtantDoc();
+}
+
 /* static */
 HighlightRegistry* CSS::GetHighlights(const GlobalObject& aGlobal,
                                       ErrorResult& aRv) {
-  nsCOMPtr<nsPIDOMWindowInner> window =
-      do_QueryInterface(aGlobal.GetAsSupports());
-  if (!window) {
-    aRv.ThrowUnknownError(
-        "There is no window associated to "
-        "this highlight registry object!");
-    return nullptr;
-  }
-
-  Document* doc = window->GetExtantDoc();
+  Document* doc = GetDocument(aGlobal);
   if (!doc) {
-    aRv.ThrowUnknownError(
-        "There is no document associated to "
-        "this highlight registry object!");
+    aRv.ThrowUnknownError("No document associated to this global?");
     return nullptr;
   }
   return &doc->HighlightRegistry();
 }
 
-}  // namespace dom
-}  // namespace mozilla
+/* static */
+void CSS::RegisterProperty(const GlobalObject& aGlobal,
+                           const PropertyDefinition& aDefinition,
+                           ErrorResult& aRv) {
+  Document* doc = GetDocument(aGlobal);
+  if (!doc) {
+    return aRv.ThrowUnknownError("No document associated to this global?");
+  }
+  doc->StyleSetForPresShellOrMediaQueryEvaluation()->RegisterProperty(
+      aDefinition, aRv);
+}
+
+}  // namespace mozilla::dom

layout/style/CSS.h

@@ -10,7 +10,7 @@
 #define mozilla_dom_CSS_h_
 
 #include "mozilla/Attributes.h"
-#include "mozilla/Preferences.h"
+#include "nsStringFwd.h"
 
 namespace mozilla {
 
@@ -20,12 +20,12 @@ namespace dom {
 
 class GlobalObject;
 class HighlightRegistry;
+struct PropertyDefinition;
 
 class CSS {
- private:
+ public:
   CSS() = delete;
 
- public:
   static bool Supports(const GlobalObject&, const nsACString& aProperty,
                        const nsACString& aValue);
 
@@ -36,6 +36,9 @@ class CSS {
 
   static HighlightRegistry* GetHighlights(const GlobalObject& aGlobal,
                                           ErrorResult& aRv);
+
+  static void RegisterProperty(const GlobalObject&, const PropertyDefinition&,
+                               ErrorResult&);
 };
 
 }  // namespace dom

layout/style/ServoStyleSet.cpp

@@ -26,6 +26,7 @@
 #include "mozilla/StyleAnimationValue.h"
 #include "mozilla/css/Loader.h"
 #include "mozilla/dom/AnonymousContent.h"
+#include "mozilla/dom/CSSBinding.h"
 #include "mozilla/dom/CSSCounterStyleRule.h"
 #include "mozilla/dom/CSSFontFaceRule.h"
 #include "mozilla/dom/CSSFontFeatureValuesRule.h"
@@ -1445,6 +1446,34 @@ void ServoStyleSet::InvalidateForViewportUnits(OnlyDynamic aOnlyDynamic) {
                                    aOnlyDynamic == OnlyDynamic::Yes);
 }
 
+void ServoStyleSet::RegisterProperty(const PropertyDefinition& aDefinition,
+                                     ErrorResult& aRv) {
+  using Result = StyleRegisterCustomPropertyResult;
+  auto result = Servo_RegisterCustomProperty(
+      RawData(), &aDefinition.mName, &aDefinition.mSyntax,
+      aDefinition.mInherits,
+      aDefinition.mInitialValue.WasPassed() ? &aDefinition.mInitialValue.Value()
+                                            : nullptr);
+  switch (result) {
+    case Result::SuccessfullyRegistered:
+      break;
+    case Result::InvalidName:
+      return aRv.ThrowSyntaxError("Invalid name");
+    case Result::InvalidSyntax:
+      return aRv.ThrowSyntaxError("Invalid syntax descriptor");
+    case Result::InvalidInitialValue:
+      return aRv.ThrowSyntaxError("Invalid initial value syntax");
+    case Result::NoInitialValue:
+      return aRv.ThrowSyntaxError(
+          "Initial value is required when syntax is not universal");
+    case Result::InitialValueNotComputationallyIndependent:
+      return aRv.ThrowSyntaxError(
+          "Initial value is required when syntax is not universal");
+    case Result::AlreadyRegistered:
+      return aRv.ThrowInvalidModificationError("Property already registered");
+  }
+}
+
 NS_IMPL_ISUPPORTS(UACacheReporter, nsIMemoryReporter)
 
 MOZ_DEFINE_MALLOC_SIZE_OF(ServoUACacheMallocSizeOf)

layout/style/ServoStyleSet.h

@@ -25,7 +25,6 @@
 #include "nsAtom.h"
 #include "nsIMemoryReporter.h"
 #include "nsTArray.h"
-#include "nsIMemoryReporter.h"
 #include "nsSize.h"
 
 namespace mozilla {
@@ -33,6 +32,8 @@ enum class MediaFeatureChangeReason : uint8_t;
 enum class StylePageSizeOrientation : uint8_t;
 enum class StyleRuleChangeKind : uint32_t;
 
+class ErrorResult;
+
 template <typename Integer, typename Number, typename LinearStops>
 struct StyleTimingFunction;
 struct StylePagePseudoClassFlags;
@@ -47,6 +48,7 @@ namespace dom {
 class CSSImportRule;
 class Element;
 class ShadowRoot;
+struct PropertyDefinition;
 }  // namespace dom
 namespace gfx {
 class FontPaletteValueSet;
@@ -660,6 +662,8 @@ class ServoStyleSet {
                            loc.second);
   }
 
+  void RegisterProperty(const dom::PropertyDefinition&, ErrorResult&);
+
  private:
   // Map of AnonymousContentKey values to an (index, length) pair pointing into
   // mCachedAnonymousContentStyles.

servo/components/style/properties_and_values/mod.rs

@@ -7,4 +7,5 @@
 //! https://drafts.css-houdini.org/css-properties-values-api-1/
 
 pub mod rule;
+pub mod registry;
 pub mod syntax;

servo/components/style/properties_and_values/registry.rs

@@ -0,0 +1,47 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+//! Registered custom properties.
+
+use crate::Atom;
+use crate::selector_map::PrecomputedHashMap;
+use super::syntax::Descriptor;
+use super::rule::InitialValue;
+
+/// A computed, already-validated property registration.
+/// <https://drafts.css-houdini.org/css-properties-values-api-1/#custom-property-registration>
+#[derive(Debug, Clone, MallocSizeOf)]
+pub struct PropertyRegistration {
+    /// The syntax of the property.
+    pub syntax: Descriptor,
+    /// Whether the property inherits.
+    pub inherits: bool,
+    /// The initial value. Only missing for universal syntax.
+    #[ignore_malloc_size_of = "Arc"]
+    pub initial_value: Option<InitialValue>,
+}
+
+/// The script registry of custom properties.
+/// <https://drafts.css-houdini.org/css-properties-values-api-1/#dom-window-registeredpropertyset-slot>
+#[derive(Default)]
+pub struct ScriptRegistry {
+    properties: PrecomputedHashMap<Atom, PropertyRegistration>,
+}
+
+impl ScriptRegistry {
+    /// Gets an already-registered custom property via script.
+    #[inline]
+    pub fn get(&self, name: &Atom) -> Option<&PropertyRegistration> {
+        self.properties.get(name)
+    }
+
+    /// Register a given property. As per
+    /// <https://drafts.css-houdini.org/css-properties-values-api-1/#the-registerproperty-function>
+    /// we don't allow overriding the registration.
+    #[inline]
+    pub fn register(&mut self, name: Atom, registration: PropertyRegistration) {
+        let old = self.properties.insert(name, registration);
+        debug_assert!(old.is_none(), "Already registered? Should be an error");
+    }
+}

servo/components/style/properties_and_values/rule.rs

@@ -9,10 +9,11 @@
 use crate::custom_properties::{Name as CustomPropertyName, SpecifiedValue};
 use crate::error_reporting::ContextualParseError;
 use crate::parser::{Parse, ParserContext};
-use crate::properties_and_values::syntax::Descriptor as SyntaxDescriptor;
+use crate::properties_and_values::syntax::{Descriptor, ParsedDescriptor};
 use crate::shared_lock::{SharedRwLockReadGuard, ToCssWithGuard};
 use crate::str::CssStringWriter;
 use crate::values::serialize_atom_name;
+use super::registry::PropertyRegistration;
 use cssparser::{
     AtRuleParser, CowRcStr, DeclarationParser, ParseErrorKind, Parser, QualifiedRuleParser,
     RuleBodyItemParser, RuleBodyParser, SourceLocation,
@@ -165,7 +166,7 @@ macro_rules! property_descriptors {
 #[cfg(feature = "gecko")]
 property_descriptors! {
     /// <https://drafts.css-houdini.org/css-properties-values-api-1/#the-syntax-descriptor>
-    "syntax" syntax: SyntaxDescriptor,
+    "syntax" syntax: ParsedDescriptor,
 
     /// <https://drafts.css-houdini.org/css-properties-values-api-1/#inherits-descriptor>
     "inherits" inherits: Inherits,
@@ -174,6 +175,16 @@ property_descriptors! {
     "initial-value" initial_value: InitialValue,
 }
 
+/// Errors that can happen when turning a property rule into a PropertyRegistration.
+#[allow(missing_docs)]
+pub enum ToRegistrationError {
+    MissingSyntax,
+    MissingInherits,
+    NoInitialValue,
+    InvalidInitialValue,
+    InitialValueNotComputationallyIndependent,
+}
+
 impl PropertyRuleData {
     /// Measure heap usage.
     #[cfg(feature = "gecko")]
@@ -187,6 +198,65 @@ impl PropertyRuleData {
                 0
             }
     }
+
+    /// Performs syntax validation as per the initial value descriptor.
+    pub fn validate_syntax(syntax: &Descriptor, initial_value: Option<&InitialValue>) -> Result<(), ToRegistrationError> {
+        // https://drafts.css-houdini.org/css-properties-values-api-1/#initial-value-descriptor:
+        //
+        //     If the value of the syntax descriptor is the universal syntax definition, then
+        //     the initial-value descriptor is optional. If omitted, the initial value of the
+        //     property is the guaranteed-invalid value.
+        //
+        //     Otherwise, if the value of the syntax descriptor is not the universal syntax
+        //     definition, the following conditions must be met for the @property rule to be
+        //     valid:
+        //
+        //       * The initial-value descriptor must be present.
+        //       * The initial-value descriptor’s value must parse successfully according to the
+        //         grammar specified by the syntax definition.
+        //       * The initial-value must be computationally independent.
+        //
+        //     If the above conditions are not met, the @property rule is invalid.
+        if !syntax.is_universal() {
+            if initial_value.is_none() {
+                return Err(ToRegistrationError::NoInitialValue);
+            }
+            // TODO(bug 1840477): Parse according to syntax (InvalidInitialValue), and ensure
+            // initial value is computationally independent
+            // (InitialValueNotComputationallyIndependent).
+        }
+        Ok(())
+    }
+
+    /// Performs relevant rule validity checks.
+    ///
+    /// If these don't pass, we shouldn't end up with a property registration.
+    ///
+    /// NOTE(emilio): Currently per spec these should happen at parse-time, but I think that's just
+    /// a spec bug, see https://github.com/w3c/css-houdini-drafts/issues/1098
+    pub fn to_valid_registration(&self) -> Result<PropertyRegistration, ToRegistrationError> {
+        use self::ToRegistrationError::*;
+
+        // https://drafts.css-houdini.org/css-properties-values-api-1/#the-syntax-descriptor:
+        //
+        //     The syntax descriptor is required for the @property rule to be valid; if it’s
+        //     missing, the @property rule is invalid.
+        let Some(ref syntax) = self.syntax else { return Err(MissingSyntax) };
+
+        // https://drafts.css-houdini.org/css-properties-values-api-1/#inherits-descriptor:
+        //
+        //     The inherits descriptor is required for the @property rule to be valid; if it’s
+        //     missing, the @property rule is invalid.
+        let Some(ref inherits) = self.inherits else { return Err(MissingInherits) };
+
+        Self::validate_syntax(syntax.descriptor(), self.initial_value.as_ref())?;
+
+        Ok(PropertyRegistration {
+            syntax: syntax.descriptor().clone(),
+            inherits: *inherits == Inherits::True,
+            initial_value: self.initial_value.clone(),
+        })
+    }
 }
 
 impl ToCssWithGuard for PropertyRuleData {
@@ -210,7 +280,7 @@ impl ToShmem for PropertyRuleData {
 
 /// A custom property name wrapper that includes the `--` prefix in its serialization
 #[derive(Clone, Debug, PartialEq)]
-pub struct PropertyRuleName(pub Arc<CustomPropertyName>);
+pub struct PropertyRuleName(pub CustomPropertyName);
 
 impl ToCss for PropertyRuleName {
     fn to_css<W: Write>(&self, dest: &mut CssWriter<W>) -> fmt::Result {

servo/components/style/properties_and_values/syntax/mod.rs

@@ -23,19 +23,59 @@ mod ascii;
 mod data_type;
 
 /// <https://drafts.css-houdini.org/css-properties-values-api-1/#parsing-syntax>
-#[derive(Debug, Clone, MallocSizeOf)]
-pub struct Descriptor {
-    components: Box<[Component]>,
-    css: String,
-}
+#[derive(Debug, Clone, Default, MallocSizeOf, PartialEq)]
+pub struct Descriptor(#[ignore_malloc_size_of = "arc"] crate::ArcSlice<Component>);
 
 impl Descriptor {
-    /// Returns the universal syntax definition with the given CSS representation.
-    fn universal(css: &str) -> Self {
-        Self {
-            components: Default::default(),
-            css: String::from(css),
+    /// Returns whether this is the universal syntax descriptor.
+    pub fn is_universal(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    /// Parse a syntax descriptor.
+    /// https://drafts.css-houdini.org/css-properties-values-api-1/#consume-a-syntax-definition
+    pub fn from_str(css: &str) -> Result<Self, ParseError> {
+        // 1. Strip leading and trailing ASCII whitespace from string.
+        let input = ascii::trim_ascii_whitespace(css);
+
+        // 2. If string's length is 0, return failure.
+        if input.is_empty() {
+            return Err(ParseError::EmptyInput);
         }
+
+        // 3. If string's length is 1, and the only code point in string is U+002A
+        //    ASTERISK (*), return the universal syntax descriptor.
+        if input.len() == 1 && input.as_bytes()[0] == b'*' {
+            return Ok(Self::default());
+        }
+
+        // 4. Let stream be an input stream created from the code points of string,
+        //    preprocessed as specified in [css-syntax-3]. Let descriptor be an
+        //    initially empty list of syntax components.
+        //
+        // NOTE(emilio): Instead of preprocessing we cheat and treat new-lines and
+        // nulls in the parser specially.
+        let mut components = vec![];
+        {
+            let mut parser = Parser::new(input, &mut components);
+            // 5. Repeatedly consume the next input code point from stream.
+            parser.parse()?;
+        }
+        Ok(Self(crate::ArcSlice::from_iter(components.into_iter())))
+    }
+}
+
+/// <https://drafts.css-houdini.org/css-properties-values-api-1/#parsing-syntax>
+#[derive(Debug, Clone, Default, MallocSizeOf, PartialEq)]
+pub struct ParsedDescriptor {
+    descriptor: Descriptor,
+    css: String
+}
+
+impl ParsedDescriptor {
+    /// Returns the specified syntax string.
+    pub fn descriptor(&self) -> &Descriptor {
+        &self.descriptor
     }
 
     /// Returns the specified syntax string.
@@ -44,13 +84,7 @@ impl Descriptor {
     }
 }
 
-impl PartialEq for Descriptor {
-    fn eq(&self, other: &Self) -> bool {
-        self.components == other.components
-    }
-}
-
-impl Parse for Descriptor {
+impl Parse for ParsedDescriptor {
     /// Parse a syntax descriptor.
     fn parse<'i, 't>(
         _context: &ParserContext,
@@ -58,14 +92,17 @@ impl Parse for Descriptor {
     ) -> Result<Self, StyleParseError<'i>> {
         // 1. Strip leading and trailing ASCII whitespace from string.
         let input = parser.expect_string()?;
-        match parse_descriptor(input) {
-            Ok(syntax) => Ok(syntax),
+        match Descriptor::from_str(input.as_ref()) {
+            Ok(descriptor) => Ok(Self {
+                descriptor,
+                css: input.as_ref().to_owned(),
+            }),
             Err(err) => Err(parser.new_custom_error(StyleParseErrorKind::PropertySyntaxField(err))),
         }
     }
 }
 
-impl ToCss for Descriptor {
+impl ToCss for ParsedDescriptor {
     fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
     where
         W: Write,
@@ -142,41 +179,6 @@ impl ComponentName {
     }
 }
 
-/// Parse a syntax descriptor.
-#[inline]
-fn parse_descriptor(css: &str) -> Result<Descriptor, ParseError> {
-    // 1. Strip leading and trailing ASCII whitespace from string.
-    let input = ascii::trim_ascii_whitespace(css);
-
-    // 2. If string's length is 0, return failure.
-    if input.is_empty() {
-        return Err(ParseError::EmptyInput);
-    }
-
-    // 3. If string's length is 1, and the only code point in string is U+002A
-    //    ASTERISK (*), return the universal syntax descriptor.
-    if input.len() == 1 && input.as_bytes()[0] == b'*' {
-        return Ok(Descriptor::universal(css));
-    }
-
-    // 4. Let stream be an input stream created from the code points of string,
-    //    preprocessed as specified in [css-syntax-3]. Let descriptor be an
-    //    initially empty list of syntax components.
-    //
-    // NOTE(emilio): Instead of preprocessing we cheat and treat new-lines and
-    // nulls in the parser specially.
-    let mut components = vec![];
-    {
-        let mut parser = Parser::new(input, &mut components);
-        // 5. Repeatedly consume the next input code point from stream.
-        parser.parse()?;
-    }
-    Ok(Descriptor {
-        components: components.into_boxed_slice(),
-        css: String::from(css),
-    })
-}
-
 struct Parser<'a> {
     input: &'a str,
     position: usize,

servo/components/style/stylesheets/rule_parser.rs

@@ -688,7 +688,7 @@ impl<'a, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'i> {
                 let name = parse_custom_property_name(&name).map_err(|_| {
                     input.new_custom_error(StyleParseErrorKind::UnexpectedIdent(name.clone()))
                 })?;
-                AtRulePrelude::Property(PropertyRuleName(Arc::new(Atom::from(name))))
+                AtRulePrelude::Property(PropertyRuleName(Atom::from(name)))
             },
             "-moz-document" if cfg!(feature = "gecko") => {
                 let cond = DocumentCondition::parse(&self.context, input)?;

servo/components/style/stylist.rs

@@ -19,6 +19,7 @@ use crate::invalidation::stylesheets::RuleChangeKind;
 use crate::media_queries::Device;
 use crate::properties::{self, CascadeMode, ComputedValues};
 use crate::properties::{AnimationDeclarations, PropertyDeclarationBlock};
+use crate::properties_and_values::registry::{ScriptRegistry as CustomPropertyScriptRegistry, PropertyRegistration};
 use crate::rule_cache::{RuleCache, RuleCacheConditions};
 use crate::rule_collector::{containing_shadow_ignoring_svg_use, RuleCollector};
 use crate::rule_tree::{CascadeLevel, RuleTree, StrongRuleNode, StyleSource};
@@ -523,6 +524,10 @@ pub struct Stylist {
     /// The rule tree, that stores the results of selector matching.
     rule_tree: RuleTree,
 
+    /// The set of registered custom properties from script.
+    /// <https://drafts.css-houdini.org/css-properties-values-api-1/#dom-window-registeredpropertyset-slot>
+    script_custom_properties: CustomPropertyScriptRegistry,
+
     /// The total number of times the stylist has been rebuilt.
     num_rebuilds: usize,
 }
@@ -612,6 +617,7 @@ impl Stylist {
             cascade_data: Default::default(),
             author_styles_enabled: AuthorStylesEnabled::Yes,
             rule_tree: RuleTree::new(),
+            script_custom_properties: Default::default(),
             num_rebuilds: 0,
         }
     }
@@ -1496,6 +1502,18 @@ impl Stylist {
         &self.rule_tree
     }
 
+    /// Returns the script-registered custom property registry.
+    #[inline]
+    pub fn custom_property_script_registry(&self) -> &CustomPropertyScriptRegistry {
+        &self.script_custom_properties
+    }
+
+    /// Returns the script-registered custom property registry, as a mutable ref.
+    #[inline]
+    pub fn custom_property_script_registry_mut(&mut self) -> &mut CustomPropertyScriptRegistry {
+        &mut self.script_custom_properties
+    }
+
     /// Measures heap usage.
     #[cfg(feature = "gecko")]
     pub fn add_size_of(&self, ops: &mut MallocSizeOfOps, sizes: &mut ServoStyleSetSizes) {
@@ -1544,6 +1562,9 @@ impl<T: 'static> LayerOrderedVec<T> {
 }
 
 impl<T: 'static> LayerOrderedMap<T> {
+    fn shrink_if_needed(&mut self) {
+        self.0.shrink_if_needed();
+    }
     fn clear(&mut self) {
         self.0.clear();
     }
@@ -2266,6 +2287,10 @@ pub struct CascadeData {
     /// by name.
     animations: LayerOrderedMap<KeyframesAnimation>,
 
+    /// A map with all the layer-ordered registrations from style at this `CascadeData`'s origin,
+    /// indexed by name.
+    custom_property_registrations: LayerOrderedMap<PropertyRegistration>,
+
     /// A map from cascade layer name to layer order.
     layer_id: FxHashMap<LayerName, LayerId>,
 
@@ -2319,6 +2344,7 @@ impl CascadeData {
             // somewhat gnarly.
             selectors_for_cache_revalidation: SelectorMap::new_without_attribute_bucketing(),
             animations: Default::default(),
+            custom_property_registrations: Default::default(),
             layer_id: Default::default(),
             layers: smallvec::smallvec![CascadeLayer::root()],
             container_conditions: smallvec::smallvec![ContainerConditionReference::none()],
@@ -2508,6 +2534,8 @@ impl CascadeData {
         if let Some(ref mut slotted_rules) = self.slotted_rules {
             slotted_rules.shrink_if_needed();
         }
+        self.animations.shrink_if_needed();
+        self.custom_property_registrations.shrink_if_needed();
         self.invalidation_map.shrink_if_needed();
         self.attribute_dependencies.shrink_if_needed();
         self.nth_of_attribute_dependencies.shrink_if_needed();
@@ -2558,6 +2586,7 @@ impl CascadeData {
         self.extra_data.sort_by_layer(&self.layers);
         self.animations
             .sort_with(&self.layers, compare_keyframes_in_same_layer);
+        self.custom_property_registrations.sort(&self.layers)
     }
 
     /// Collects all the applicable media query results into `results`.
@@ -2780,6 +2809,15 @@ impl CascadeData {
                         compare_keyframes_in_same_layer,
                     )?;
                 },
+                CssRule::Property(ref rule) => {
+                    if let Ok(registration) = rule.to_valid_registration() {
+                        self.custom_property_registrations.try_insert(
+                            rule.name.0.clone(),
+                            registration,
+                            containing_rule_state.layer_id,
+                        )?;
+                    }
+                },
                 #[cfg(feature = "gecko")]
                 CssRule::FontFace(ref rule) => {
                     // NOTE(emilio): We don't care about container_condition_id
@@ -3129,6 +3167,7 @@ impl CascadeData {
             host_rules.clear();
         }
         self.animations.clear();
+        self.custom_property_registrations.clear();
         self.layer_id.clear();
         self.layers.clear();
         self.layers.push(CascadeLayer::root());

servo/ports/geckolib/glue.rs

@@ -7817,3 +7817,83 @@ pub extern "C" fn Servo_ParseAbsoluteLength(len: &nsACString, out: &mut f32) ->
         Err(..) => false,
     }
 }
+
+#[repr(u8)]
+pub enum RegisterCustomPropertyResult {
+    SuccessfullyRegistered,
+    InvalidName,
+    AlreadyRegistered,
+    InvalidSyntax,
+    NoInitialValue,
+    InvalidInitialValue,
+    InitialValueNotComputationallyIndependent,
+}
+
+/// https://drafts.css-houdini.org/css-properties-values-api-1/#the-registerproperty-function
+#[no_mangle]
+pub extern "C" fn Servo_RegisterCustomProperty(
+    per_doc_data: &PerDocumentStyleData,
+    name: &nsACString,
+    syntax: &nsACString,
+    inherits: bool,
+    initial_value: Option<&nsACString>,
+) -> RegisterCustomPropertyResult {
+    use self::RegisterCustomPropertyResult::*;
+    use style::custom_properties::SpecifiedValue;
+    use style::properties_and_values::registry::PropertyRegistration;
+    use style::properties_and_values::rule::{PropertyRuleData, ToRegistrationError};
+    use style::properties_and_values::syntax::Descriptor;
+
+    let mut per_doc_data = per_doc_data.borrow_mut();
+    let name = unsafe { name.as_str_unchecked() };
+    let syntax = unsafe { syntax.as_str_unchecked() };
+    let initial_value = initial_value.map(|v| unsafe { v.as_str_unchecked() });
+
+    // If name is not a custom property name string, throw a SyntaxError and exit this algorithm.
+    let name = match style::custom_properties::parse_name(name) {
+        Ok(n) => Atom::from(n),
+        Err(()) => return InvalidName,
+    };
+
+    // If property set already contains an entry with name as its property name (compared
+    // codepoint-wise), throw an InvalidModificationError and exit this algorithm.
+    if per_doc_data.stylist.custom_property_script_registry().get(&name).is_some() {
+        return AlreadyRegistered
+    }
+    // Attempt to consume a syntax definition from syntax. If it returns failure, throw a
+    // SyntaxError. Otherwise, let syntax definition be the returned syntax definition.
+    let Ok(syntax) = Descriptor::from_str(syntax) else { return InvalidSyntax };
+
+    let initial_value = match initial_value {
+        Some(v) => {
+            let mut input = ParserInput::new(v);
+            let parsed = Parser::new(&mut input).parse_entirely(|input| {
+                input.skip_whitespace();
+                SpecifiedValue::parse(input)
+            }).ok();
+            if parsed.is_none() {
+                return InvalidInitialValue
+            }
+            parsed
+        }
+        None => None,
+    };
+
+    if let Err(error) = PropertyRuleData::validate_syntax(&syntax, initial_value.as_ref()) {
+        return match error {
+            ToRegistrationError::MissingInherits |
+            ToRegistrationError::MissingSyntax => unreachable!(),
+            ToRegistrationError::InitialValueNotComputationallyIndependent => InitialValueNotComputationallyIndependent,
+            ToRegistrationError::InvalidInitialValue => InvalidInitialValue,
+            ToRegistrationError::NoInitialValue=> NoInitialValue,
+        }
+    }
+
+    per_doc_data.stylist.custom_property_script_registry_mut().register(name, PropertyRegistration {
+        syntax,
+        inherits,
+        initial_value,
+    });
+
+    SuccessfullyRegistered
+}

testing/web-platform/meta/css/css-anchor-position/anchor-query-custom-property-registration.html.ini

@@ -1,4 +1,14 @@
 [anchor-query-custom-property-registration.html]
   expected:
     if (os == "android") and fission: [ERROR, TIMEOUT]
-    ERROR
+  [anchor() cannot be used as <length> initial value]
+    expected: FAIL
+
+  [anchor-size() cannot be used as <length> initial value]
+    expected: FAIL
+
+  [anchor() cannot be used as <length-percentage> initial value]
+    expected: FAIL
+
+  [anchor-size() cannot be used as <length-percentage> initial value]
+    expected: FAIL

testing/web-platform/meta/css/css-animations/animation-important-001.html.ini

@@ -1,4 +1,5 @@
 [animation-important-001.html]
   expected:
     if (os == "android") and fission: [ERROR, TIMEOUT]
-    ERROR
+  [Custom property animations appearing via setKeyframes do not override important declarations]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-angle-comma-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-angle-comma-list.html]
-  expected: ERROR
+  [Animating a custom property of type <angle>#]
+    expected: FAIL
+
+  [Animating a custom property of type <angle># with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <angle># with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <angle># with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <angle># with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <angle># with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-angle-space-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-angle-space-list.html]
-  expected: ERROR
+  [Animating a custom property of type <angle>+]
+    expected: FAIL
+
+  [Animating a custom property of type <angle>+ with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <angle>+ with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <angle>+ with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <angle>+ with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <angle>+ with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-angle.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-angle.html]
-  expected: ERROR
+  [Animating a custom property of type <angle>]
+    expected: FAIL
+
+  [Animating a custom property of type <angle> with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <angle> with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <angle> with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <angle> with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-color-comma-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-color-comma-list.html]
-  expected: ERROR
+  [Animating a custom property of type <color>#]
+    expected: FAIL
+
+  [Animating a custom property of type <color># with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <color># with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <color># with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <color># with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <color># with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-color-space-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-color-space-list.html]
-  expected: ERROR
+  [Animating a custom property of type <color>+]
+    expected: FAIL
+
+  [Animating a custom property of type <color>+ with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <color>+ with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <color>+ with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <color>+ with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <color>+ with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-color.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-color.html]
-  expected: ERROR
+  [Animating a custom property of type <color>]
+    expected: FAIL
+
+  [Animating a custom property of type <color> with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <color> with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <color> with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <color> with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-integer-comma-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-integer-comma-list.html]
-  expected: ERROR
+  [Animating a custom property of type <integer>#]
+    expected: FAIL
+
+  [Animating a custom property of type <integer># with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <integer># with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <integer># with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <integer># with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <integer># with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-integer-space-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-integer-space-list.html]
-  expected: ERROR
+  [Animating a custom property of type <integer>+]
+    expected: FAIL
+
+  [Animating a custom property of type <integer>+ with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <integer>+ with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <integer>+ with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <integer>+ with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <integer>+ with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-integer.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-integer.html]
-  expected: ERROR
+  [Animating a custom property of type <integer>]
+    expected: FAIL
+
+  [Animating a custom property of type <integer> with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <integer> with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <integer> with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <integer> with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-length-comma-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-length-comma-list.html]
-  expected: ERROR
+  [Animating a custom property of type <length>#]
+    expected: FAIL
+
+  [Animating a custom property of type <length># with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <length># with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length># with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length># with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <length># with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-length-percentage-comma-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-length-percentage-comma-list.html]
-  expected: ERROR
+  [Animating a custom property of type <length-percentage>#]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage># with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage># with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage># with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage># with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage># with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-length-percentage-space-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-length-percentage-space-list.html]
-  expected: ERROR
+  [Animating a custom property of type <length-percentage>+]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage>+ with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage>+ with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage>+ with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage>+ with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage>+ with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-length-percentage.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-length-percentage.html]
-  expected: ERROR
+  [Animating a custom property of type <length-percentage>]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage> with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage> with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage> with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length-percentage> with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-length-space-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-length-space-list.html]
-  expected: ERROR
+  [Animating a custom property of type <length>+]
+    expected: FAIL
+
+  [Animating a custom property of type <length>+ with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <length>+ with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length>+ with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length>+ with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <length>+ with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-length.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-length.html]
-  expected: ERROR
+  [Animating a custom property of type <length>]
+    expected: FAIL
+
+  [Animating a custom property of type <length> with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <length> with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length> with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <length> with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-list-type-mismatch.html.ini

@@ -1,2 +1,3 @@
 [custom-property-animation-list-type-mismatch.html]
-  expected: ERROR
+  [Animating a custom property allowing multiple list types with two mismatching types]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-number-comma-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-number-comma-list.html]
-  expected: ERROR
+  [Animating a custom property of type <number>#]
+    expected: FAIL
+
+  [Animating a custom property of type <number># with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <number># with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <number># with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <number># with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <number># with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-number-space-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-number-space-list.html]
-  expected: ERROR
+  [Animating a custom property of type <number>+]
+    expected: FAIL
+
+  [Animating a custom property of type <number>+ with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <number>+ with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <number>+ with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <number>+ with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <number>+ with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-number.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-number.html]
-  expected: ERROR
+  [Animating a custom property of type <number>]
+    expected: FAIL
+
+  [Animating a custom property of type <number> with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <number> with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <number> with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <number> with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-percentage-comma-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-percentage-comma-list.html]
-  expected: ERROR
+  [Animating a custom property of type <percentage>#]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage># with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage># with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage># with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage># with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage># with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-percentage-space-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-percentage-space-list.html]
-  expected: ERROR
+  [Animating a custom property of type <percentage>+]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage>+ with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage>+ with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage>+ with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage>+ with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage>+ with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-percentage.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-percentage.html]
-  expected: ERROR
+  [Animating a custom property of type <percentage>]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage> with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage> with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage> with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <percentage> with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-resolution-comma-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-resolution-comma-list.html]
-  expected: ERROR
+  [Animating a custom property of type <resolution>#]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution># with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution># with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution># with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution># with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution># with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-resolution-space-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-resolution-space-list.html]
-  expected: ERROR
+  [Animating a custom property of type <resolution>+]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution>+ with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution>+ with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution>+ with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution>+ with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution>+ with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-resolution.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-resolution.html]
-  expected: ERROR
+  [Animating a custom property of type <resolution>]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution> with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution> with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution> with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <resolution> with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-time-comma-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-time-comma-list.html]
-  expected: ERROR
+  [Animating a custom property of type <time>#]
+    expected: FAIL
+
+  [Animating a custom property of type <time># with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <time># with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <time># with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <time># with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <time># with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-time-space-list.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-time-space-list.html]
-  expected: ERROR
+  [Animating a custom property of type <time>+]
+    expected: FAIL
+
+  [Animating a custom property of type <time>+ with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <time>+ with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <time>+ with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <time>+ with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <time>+ with different lengths is discrete]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-time.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-time.html]
-  expected: ERROR
+  [Animating a custom property of type <time>]
+    expected: FAIL
+
+  [Animating a custom property of type <time> with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <time> with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <time> with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <time> with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-transform-function.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-transform-function.html]
-  expected: ERROR
+  [Animating a custom property of type <transform-function>]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-function> with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-function> with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-function> with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-function> with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-transform-list-multiple-values.html.ini

@@ -1,2 +1,18 @@
 [custom-property-animation-transform-list-multiple-values.html]
-  expected: ERROR
+  [Animating a custom property of type <transform-list> containing multiple values]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-list> containing multiple values with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-list> containing multiple values with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-list> containing multiple values with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-list> containing multiple values with iterationComposite]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-list> containing multiple values and with mismatching list lengths]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/animation/custom-property-animation-transform-list-single-values.html.ini

@@ -1,2 +1,15 @@
 [custom-property-animation-transform-list-single-values.html]
-  expected: ERROR
+  [Animating a custom property of type <transform-list> containing a single value]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-list> containing a single value with a single keyframe]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-list> containing a single value with additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-list> containing a single value with a single keyframe and additivity]
+    expected: FAIL
+
+  [Animating a custom property of type <transform-list> containing a single value with iterationComposite]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/conditional-rules.html.ini

@@ -1,2 +0,0 @@
-[conditional-rules.html]
-  expected: ERROR

testing/web-platform/meta/css/css-properties-values-api/font-size-animation.html.ini

@@ -1,2 +1,3 @@
 [font-size-animation.html]
-  expected: ERROR
+  [Animating font-size handled identically for standard and custom properties]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/idlharness.html.ini

@@ -1,10 +1,6 @@
 [idlharness.html]
   expected:
-    if debug and (os == "linux"): ["OK", "TIMEOUT"]
-  [CSS namespace: operation registerProperty(PropertyDefinition)]
-    expected: FAIL
-
+    if debug and (os == "linux"): [OK, TIMEOUT]
   [idl_test setup]
     expected:
-      if debug and (os == "linux"): ["PASS", "TIMEOUT"]
-
+      if debug and (os == "linux"): [PASS, TIMEOUT]

testing/web-platform/meta/css/css-properties-values-api/register-property-syntax-parsing.html.ini

@@ -1,235 +1,7 @@
 [register-property-syntax-parsing.html]
-  [syntax:'*', initialValue:'a' is valid]
-    expected: FAIL
-
-  [syntax:' * ', initialValue:'b' is valid]
-    expected: FAIL
-
-  [syntax:'<length>', initialValue:'2px' is valid]
-    expected: FAIL
-
-  [syntax:' <number>', initialValue:'5' is valid]
-    expected: FAIL
-
-  [syntax:'<percentage> ', initialValue:'10%' is valid]
-    expected: FAIL
-
-  [syntax:'<color>+', initialValue:'red' is valid]
-    expected: FAIL
-
-  [syntax:' <length>+ | <percentage>', initialValue:'2px 8px' is valid]
-    expected: FAIL
-
-  [syntax:'<length>|<percentage>|<length-percentage>', initialValue:'2px' is valid]
-    expected: FAIL
-
-  [syntax:'<color> | <image> | <url> | <integer> | <angle>', initialValue:'red' is valid]
-    expected: FAIL
-
-  [syntax:'<time> | <resolution> | <transform-list> | <custom-ident>', initialValue:'red' is valid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:':> hello' is valid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'([ brackets \]) { yay (??)}' is valid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'yep 'this is valid too'' is valid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'unmatched opening bracket is valid :(' is valid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'"' is valid]
-    expected: FAIL
-
-  [syntax:'<length>', initialValue:'0' is valid]
-    expected: FAIL
-
-  [syntax:'<length>', initialValue:'10px /*:)*/' is valid]
-    expected: FAIL
-
-  [syntax:'<length>', initialValue:' calc(-2px)' is valid]
-    expected: FAIL
-
-  [syntax:'<length>', initialValue:'calc(2px*4 + 10px)' is valid]
-    expected: FAIL
-
-  [syntax:'<length>', initialValue:'7.1e-4cm' is valid]
-    expected: FAIL
-
-  [syntax:'<length>', initialValue:'calc(7in - 12px)' is valid]
-    expected: FAIL
-
-  [syntax:'<length>+', initialValue:'2px 7px calc(8px)' is valid]
-    expected: FAIL
-
-  [syntax:'<percentage>', initialValue:'-9.3e3%' is valid]
-    expected: FAIL
-
-  [syntax:'<length-percentage>', initialValue:'-54%' is valid]
-    expected: FAIL
-
-  [syntax:'<length-percentage>', initialValue:'0' is valid]
-    expected: FAIL
-
-  [syntax:'<length-percentage>', initialValue:'calc(-11px + 10.4%)' is valid]
-    expected: FAIL
-
-  [syntax:'<number>', initialValue:'-109' is valid]
-    expected: FAIL
-
-  [syntax:'<number>', initialValue:'2.3e4' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>', initialValue:'-109' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>', initialValue:'19' is valid]
-    expected: FAIL
-
-  [syntax:'<angle>', initialValue:'10deg' is valid]
-    expected: FAIL
-
-  [syntax:'<angle>', initialValue:'20.5rad' is valid]
-    expected: FAIL
-
-  [syntax:'<angle>', initialValue:'calc(50grad + 3.14159rad)' is valid]
-    expected: FAIL
-
-  [syntax:'<time>', initialValue:'2s' is valid]
-    expected: FAIL
-
-  [syntax:'<time>', initialValue:'calc(2s - 9ms)' is valid]
-    expected: FAIL
-
-  [syntax:'<resolution>', initialValue:'10dpi' is valid]
-    expected: FAIL
-
-  [syntax:'<resolution>', initialValue:'3dPpX' is valid]
-    expected: FAIL
-
-  [syntax:'<resolution>', initialValue:'-5.3dpcm' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-list>', initialValue:'scale(2)' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-list>', initialValue:'translateX(2px) rotate(20deg)' is valid]
-    expected: FAIL
-
-  [syntax:'<color>', initialValue:'rgb(12, 34, 56)' is valid]
-    expected: FAIL
-
-  [syntax:'<color>', initialValue:'lightgoldenrodyellow' is valid]
-    expected: FAIL
-
-  [syntax:'<image>', initialValue:'url(a)' is valid]
-    expected: FAIL
-
-  [syntax:'<image>', initialValue:'linear-gradient(yellow, blue)' is valid]
-    expected: FAIL
-
-  [syntax:'<url>', initialValue:'url(a)' is valid]
-    expected: FAIL
-
-  [syntax:'banana', initialValue:'banana' is valid]
-    expected: FAIL
-
-  [syntax:'bAnAnA', initialValue:'bAnAnA' is valid]
-    expected: FAIL
-
-  [syntax:'ba-na-nya', initialValue:'ba-na-nya' is valid]
-    expected: FAIL
-
-  [syntax:'banana', initialValue:'banan\\61' is valid]
-    expected: FAIL
-
-  [syntax:'<custom-ident>', initialValue:'banan\\61' is valid]
-    expected: FAIL
-
-  [syntax:'big | bigger | BIGGER', initialValue:'bigger' is valid]
-    expected: FAIL
-
-  [syntax:'foo+|bar', initialValue:'foo foo foo' is valid]
-    expected: FAIL
-
-  [syntax:'banana\t', initialValue:'banana' is valid]
-    expected: FAIL
-
-  [syntax:'\nbanana\r\n', initialValue:'banana' is valid]
-    expected: FAIL
-
   [syntax:'ba\x0c\n|\tna\r|nya', initialValue:'nya' is valid]
     expected: FAIL
 
-  [syntax:'null', initialValue:'null' is valid]
-    expected: FAIL
-
-  [syntax:'undefined', initialValue:'undefined' is valid]
-    expected: FAIL
-
-  [syntax:'array', initialValue:'array' is valid]
-    expected: FAIL
-
-  [syntax:'banana,nya', initialValue:'banana' is invalid]
-    expected: FAIL
-
-  [syntax:'<\\6c ength>', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'<banana>', initialValue:'banana' is invalid]
-    expected: FAIL
-
-  [syntax:'<Number>', initialValue:'10' is invalid]
-    expected: FAIL
-
-  [syntax:'<length', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'<LENGTH>', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'< length>', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'<length >', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'<length> +', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'<length>++', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'<length> | *', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'*|banana', initialValue:'banana' is invalid]
-    expected: FAIL
-
-  [syntax:'*+', initialValue:'banana' is invalid]
-    expected: FAIL
-
-  [syntax:'initial', initialValue:'initial' is invalid]
-    expected: FAIL
-
-  [syntax:'inherit', initialValue:'inherit' is invalid]
-    expected: FAIL
-
-  [syntax:'unset', initialValue:'unset' is invalid]
-    expected: FAIL
-
-  [syntax:'<length>|initial', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'<length>|INHERIT', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'<percentage>|unsEt', initialValue:'2%' is invalid]
-    expected: FAIL
-
   [syntax:'*', initialValue:'initial' is invalid]
     expected: FAIL
 
@@ -248,27 +20,6 @@
   [syntax:'<custom-ident>+', initialValue:'foo inherit bar' is invalid]
     expected: FAIL
 
-  [syntax:'*', initialValue:')' is invalid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'([)\]' is invalid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'whee!' is invalid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'"\n' is invalid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'url(moo '')' is invalid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'semi;colon' is invalid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'var(invalid var ref)' is invalid]
-    expected: FAIL
-
   [syntax:'*', initialValue:'var(--foo)' is invalid]
     expected: FAIL
 
@@ -305,9 +56,6 @@
   [syntax:'<length>+', initialValue:'10px calc(20px + 4rem)' is invalid]
     expected: FAIL
 
-  [syntax:'<length>', initialValue:'10px;' is invalid]
-    expected: FAIL
-
   [syntax:'<length-percentage>', initialValue:'calc(2px + 10% + 7ex)' is invalid]
     expected: FAIL
 
@@ -338,9 +86,6 @@
   [syntax:'<transform-list>', initialValue:'scale()' is invalid]
     expected: FAIL
 
-  [syntax:'<transform-list>+', initialValue:'translateX(2px) rotate(20deg)' is invalid]
-    expected: FAIL
-
   [syntax:'<color>', initialValue:'fancy-looking' is invalid]
     expected: FAIL
 
@@ -350,120 +95,18 @@
   [syntax:'<url>', initialValue:'banana.png' is invalid]
     expected: FAIL
 
-  [syntax:'<transform-function>', initialValue:'translateX(2px)' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-function>|<integer>', initialValue:'5' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-function>|<integer>', initialValue:'scale(2)' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-function>+', initialValue:'translateX(2px) rotate(42deg)' is valid]
-    expected: FAIL
-
   [syntax:'<transform-function>', initialValue:'scale()' is invalid]
     expected: FAIL
 
-  [syntax:'<integer>', initialValue:'calc(1 + 2)' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>', initialValue:'calc(3.1415)' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>', initialValue:'calc(1)' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>', initialValue:'calc(3.1415 + 3.1415)' is valid]
-    expected: FAIL
-
-  [syntax:'<length>#', initialValue:'2px, 7px, calc(8px)' is valid]
-    expected: FAIL
-
   [syntax:'<length>#', initialValue:'' is invalid]
     expected: FAIL
 
   [syntax:'<length>+', initialValue:'' is invalid]
     expected: FAIL
 
-  [syntax:'<transform-list>+', initialValue:'scale(2)' is invalid]
-    expected: FAIL
-
-  [syntax:'\\1F914 hmm', initialValue:'🤔hmm' is valid]
-    expected: FAIL
-
-  [syntax:'<length>#+', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:' <length>+ | <color>#', initialValue:'red, blue' is valid]
-    expected: FAIL
-
-  [syntax:'|banana', initialValue:'banana' is invalid]
-    expected: FAIL
-
-  [syntax:'hmm\\1F914', initialValue:'hmm🤔' is valid]
-    expected: FAIL
-
-  [syntax:'\\1F914\\1F914', initialValue:'🤔🤔' is valid]
-    expected: FAIL
-
-  [syntax:'||', initialValue:'banana' is invalid]
-    expected: FAIL
-
-  [syntax:'\t<color>\n|   foo', initialValue:'foo' is valid]
-    expected: FAIL
-
-  [syntax:'\\1F914', initialValue:'🤔' is valid]
-    expected: FAIL
-
-  [syntax:'<length>+#', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:'\\1F914hmm', initialValue:'🤔hmm' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-list>#', initialValue:'scale(2)' is invalid]
-    expected: FAIL
-
-  [syntax:'banan\\61', initialValue:'banana' is valid]
-    expected: FAIL
-
-  [syntax:'|', initialValue:'banana' is invalid]
-    expected: FAIL
-
-  [syntax:'<length>##', initialValue:'10px' is invalid]
-    expected: FAIL
-
-  [syntax:' |', initialValue:'banana' is invalid]
-    expected: FAIL
-
-  [syntax:'\\1F914 hmm', initialValue:'🤔hmm' is valid]
-    expected: FAIL
-
-  [syntax:'default', initialValue:'default' is invalid]
-    expected: FAIL
-
-  [syntax:'hmm\\1F914', initialValue:'hmm🤔' is valid]
-    expected: FAIL
-
-  [syntax:'\\1F914\\1F914', initialValue:'🤔🤔' is valid]
-    expected: FAIL
-
-  [syntax:'<color>|REVert', initialValue:'red' is invalid]
-    expected: FAIL
-
-  [syntax:'\\1F914', initialValue:'🤔' is valid]
-    expected: FAIL
-
   [syntax:'<custom-ident>', initialValue:'default' is invalid]
     expected: FAIL
 
-  [syntax:'\\1F914hmm', initialValue:'🤔hmm' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>|deFAUlt', initialValue:'1' is invalid]
-    expected: FAIL
-
   [syntax:'<custom-ident>+', initialValue:'foo revert bar' is invalid]
     expected: FAIL
 
@@ -473,9 +116,6 @@
   [syntax:'<custom-ident>+', initialValue:'foo default bar' is invalid]
     expected: FAIL
 
-  [syntax:'revert', initialValue:'revert' is invalid]
-    expected: FAIL
-
   [syntax:'<custom-ident>+', initialValue:'foo unset bar' is invalid]
     expected: FAIL
 
@@ -488,36 +128,12 @@
   [syntax:'<custom-ident>', initialValue:'unset' is invalid]
     expected: FAIL
 
-  [syntax:'foo § bar', initialValue:'foo § bar' is invalid]
-    expected: FAIL
-
   [syntax:'Foo | bar', initialValue:'Bar' is invalid]
     expected: FAIL
 
-  [syntax:'<length> <number>', initialValue:'0px 0' is invalid]
-    expected: FAIL
-
   [syntax:'Foo | bar', initialValue:'foo' is invalid]
     expected: FAIL
 
-  [syntax:'<length> <length> <length>', initialValue:'0px 0px 0px' is invalid]
-    expected: FAIL
-
-  [syntax:'foo bar', initialValue:'foo bar' is invalid]
-    expected: FAIL
-
-  [syntax:'foo foo foo', initialValue:'foo foo foo' is invalid]
-    expected: FAIL
-
-  [syntax:'foo \\1F914 bar', initialValue:'foo \\1F914 bar' is invalid]
-    expected: FAIL
-
-  [syntax:'<percentage> | <length>+', initialValue:'calc(100vh - 10px) 30px' is valid]
-    expected: FAIL
-
-  [syntax:'<length>', initialValue:'10vmin' is valid]
-    expected: FAIL
-
   [syntax:'<custom-ident>+', initialValue:'foo revert-layer bar' is invalid]
     expected: FAIL
 
@@ -527,107 +143,20 @@
   [syntax:'<custom-ident>', initialValue:'revert-layer' is invalid]
     expected: FAIL
 
-  [syntax:'revert-layer', initialValue:'revert-layer' is invalid]
-    expected: FAIL
-
-  [syntax:'*', initialValue:'default' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1% 1%' is valid]
-    expected: FAIL
-
   [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1px 1%' is invalid]
     expected: FAIL
 
-  [syntax:'<transform-list> | <transform-function># ', initialValue:'scale(2) rotate(90deg)' is valid]
-    expected: FAIL
-
-  [syntax:'<color># | yellow', initialValue:'yellow, blue' is valid]
-    expected: FAIL
-
   [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1 1%' is invalid]
     expected: FAIL
 
   [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1% 1' is invalid]
     expected: FAIL
 
-  [syntax:'<transform-list> | <transform-function># ', initialValue:'scale(2), rotate(90deg)' is valid]
-    expected: FAIL
-
-  [syntax:'<color># | <color>+', initialValue:'yellow blue' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1 1' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-function> | <transform-list>', initialValue:'scale(2) rotate(90deg)' is valid]
-    expected: FAIL
-
-  [syntax:'<color>+ | yellow', initialValue:'yellow blue' is valid]
-    expected: FAIL
-
   [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1% 1px' is invalid]
     expected: FAIL
 
-  [syntax:'<color>+ | <color>', initialValue:'yellow blue' is valid]
-    expected: FAIL
-
-  [syntax:'yellow', initialValue:'yellow' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-list> | <transform-function>+ ', initialValue:'scale(2) rotate(90deg)' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-function>+ | <transform-list>', initialValue:'scale(2) rotate(90deg)' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1%' is valid]
-    expected: FAIL
-
-  [syntax:'<color> | <color>#', initialValue:'yellow, blue' is valid]
-    expected: FAIL
-
-  [syntax:'yellow | <color>+', initialValue:'yellow blue' is valid]
-    expected: FAIL
-
   [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1 1px' is invalid]
     expected: FAIL
 
-  [syntax:'<color>+', initialValue:'yellow blue' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-function># | <transform-list>', initialValue:'scale(2) rotate(90deg)' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1px' is valid]
-    expected: FAIL
-
-  [syntax:'<color>+ | <color>#', initialValue:'yellow, blue' is valid]
-    expected: FAIL
-
-  [syntax:'yellow | <color>#', initialValue:'yellow, blue' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1px 1px' is valid]
-    expected: FAIL
-
-  [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-list> | <transform-function> ', initialValue:'scale(2) rotate(90deg)' is valid]
-    expected: FAIL
-
-  [syntax:'<color># | <color>', initialValue:'yellow, blue' is valid]
-    expected: FAIL
-
-  [syntax:'<transform-function># | <transform-list>', initialValue:'scale(2), rotate(90deg)' is valid]
-    expected: FAIL
-
   [syntax:'<integer>+ | <percentage>+ | <length>+ ', initialValue:'1px 1' is invalid]
     expected: FAIL
-
-  [syntax:'<color> | <color>+', initialValue:'yellow blue' is valid]
-    expected: FAIL
-
-  [syntax:'<number>', initialValue:'calc(1 / 2)' is valid]
-    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/register-property.html.ini

@@ -1,16 +1,3 @@
 [register-property.html]
-  [registerProperty requires a name matching <custom-property-name>]
-    expected: FAIL
-
-  [registerProperty fails for an already registered property]
-    expected: FAIL
-
-  [registerProperty only allows omitting initialValue if syntax is '*']
-    expected: FAIL
-
-  [registerProperty requires inherits]
-    expected: FAIL
-
   [Registering a property should not cause a transition]
     expected: FAIL
-

testing/web-platform/meta/css/css-properties-values-api/registered-properties-inheritance.html.ini

@@ -19,6 +19,3 @@
 
   [Calc expressions are resolved before inheritance]
     expected: FAIL
-
-  [Explicitly inheriting from a parent with a value results in that value.]
-    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/registered-property-computation.html.ini

@@ -20,39 +20,21 @@
   [<integer>+ values are computed correctly [15 calc(2.4) calc(2.6)\]]
     expected: FAIL
 
-  [<integer> values are computed correctly [15\]]
-    expected: FAIL
-
-  [* values are computed correctly [50dpi\]]
-    expected: FAIL
-
   [<color> values are computed correctly [#badbee33\]]
     expected: FAIL
 
   [<time> values are computed correctly [calc(1000ms + 1s)\]]
     expected: FAIL
 
-  [<transform-function>+ values are computed correctly [translateX(10%) scale(2)\]]
-    expected: FAIL
-
   [<length-percentage># values are computed correctly [3% , 10vmax  , 22px\]]
     expected: FAIL
 
-  [tomato | plum values are computed correctly [plum\]]
-    expected: FAIL
-
-  [<color> values are computed correctly [currentcolor\]]
-    expected: FAIL
-
   [<resolution> values are computed correctly [96dpi\]]
     expected: FAIL
 
   [<length> values computed are correctly via var()-reference when font-size is inherited]
     expected: FAIL
 
-  [* values are computed correctly [-50grad\]]
-    expected: FAIL
-
   [<length># values are computed correctly [8em\]]
     expected: FAIL
 
@@ -62,9 +44,6 @@
   [<time> values are computed correctly [1000ms\]]
     expected: FAIL
 
-  [<transform-function> values are computed correctly [translateX(2px)\]]
-    expected: FAIL
-
   [<length>+ values are computed correctly [4em 9px\]]
     expected: FAIL
 
@@ -92,9 +71,6 @@
   [<length> values are computed correctly [15vmin\]]
     expected: FAIL
 
-  [tomato | plum | <color> values are computed correctly [plum\]]
-    expected: FAIL
-
   [<length-percentage> values are computed correctly [calc(19em - 2%)\]]
     expected: FAIL
 
@@ -104,18 +80,12 @@
   [<integer> values are computed correctly [calc(2.6)\]]
     expected: FAIL
 
-  [<length-percentage> values are computed correctly [18%\]]
-    expected: FAIL
-
   [<transform-function> values are computed correctly [translateX(calc(11em + 10%))\]]
     expected: FAIL
 
   [<length> values computed are correctly via var()-reference]
     expected: FAIL
 
-  [* values are computed correctly [50s\]]
-    expected: FAIL
-
   [<length> values are computed correctly when font-size is inherited [14em\]]
     expected: FAIL
 
@@ -125,15 +95,6 @@
   [<color> values are computed correctly [#00000a\]]
     expected: FAIL
 
-  [<angle> values are computed correctly [180deg\]]
-    expected: FAIL
-
-  [<resolution> values are computed correctly [1dppx\]]
-    expected: FAIL
-
-  [<time> values are computed correctly [1s\]]
-    expected: FAIL
-
   [<length> values are computed correctly [calc(16px - 7em + 10vh)\]]
     expected: FAIL
 
@@ -143,21 +104,12 @@
   [<length># values are computed correctly [4em ,9px\]]
     expected: FAIL
 
-  [<length-percentage># values are computed correctly [calc(13% + 37px)\]]
-    expected: FAIL
-
-  [<length> values are computed correctly [12px\]]
-    expected: FAIL
-
   [<length-percentage> values are computed correctly [17em\]]
     expected: FAIL
 
   [<transform-function> values are computed correctly [translateX(10em)\]]
     expected: FAIL
 
-  [* values are computed correctly [tomato\]]
-    expected: FAIL
-
   [<integer> values are computed correctly [calc(2.6 + 3.1)\]]
     expected: FAIL
 
@@ -182,15 +134,9 @@
   [<length> values are computed correctly [10lh\]]
     expected: FAIL
 
-  [* values are computed correctly [url(why)\]]
-    expected: FAIL
-
   [<number> values are computed correctly [calc(24 / 10)\]]
     expected: FAIL
 
-  [<number> values are computed correctly [15\]]
-    expected: FAIL
-
   [<number>+ values are computed correctly [15 calc(15 + 15) calc(24 / 10)\]]
     expected: FAIL
 

testing/web-platform/meta/css/css-properties-values-api/registered-property-cssom.html.ini

@@ -1,7 +1,4 @@
 [registered-property-cssom.html]
-  [CSS.registerProperty]
-    expected: FAIL
-
   [Formerly valid values are still readable from inline styles but are computed as the unset value]
     expected: FAIL
 

testing/web-platform/meta/css/css-properties-values-api/registered-property-revert.html.ini

@@ -1,2 +1,9 @@
 [registered-property-revert.html]
-  expected: ERROR
+  [Non-inherited registered custom property can be reverted]
+    expected: FAIL
+
+  [Non-inherited registered custom property can be reverted in animation]
+    expected: FAIL
+
+  [Inherited registered custom property can be reverted in animation]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/self-utils.html.ini

@@ -1,7 +1,3 @@
 [self-utils.html]
-  [Default initial values of generated properties are valid (self-test).]
-    expected: FAIL
-
   [Generated properties respect inherits flag]
     expected: FAIL
-

testing/web-platform/meta/css/css-properties-values-api/url-resolution.html.ini

@@ -1,2 +1,48 @@
 [url-resolution.html]
-  expected: ERROR
+  [Registered non-inherited <url> resolves against sheet (URL token)]
+    expected: FAIL
+
+  [Registered non-inherited <url> resolves against sheet (URL function)]
+    expected: FAIL
+
+  [Registered inherited <url> resolves against sheet (URL token)]
+    expected: FAIL
+
+  [Registered inherited <url> resolves against sheet (URL function)]
+    expected: FAIL
+
+  [Registered inherited <url> resolves against sheet (Child node, URL token)]
+    expected: FAIL
+
+  [Registered inherited <url> resolves against sheet (Child node, URL function)]
+    expected: FAIL
+
+  [Registered property with unregistered var reference resolves against sheet (URL token)]
+    expected: FAIL
+
+  [Registered property with unregistered var reference resolves against sheet. (URL function)]
+    expected: FAIL
+
+  [Registered property with registered var reference resolves against sheet of referenced property (URL token)]
+    expected: FAIL
+
+  [Registered property with registered var reference resolves against sheet of referenced property (URL function)]
+    expected: FAIL
+
+  [Unregistered property with registered var reference resolves against sheet of referenced property (URL token)]
+    expected: FAIL
+
+  [Unregistered property with registered var reference resolves against sheet of referenced property (URL function)]
+    expected: FAIL
+
+  [Multiple (registered) var reference resolve against respective sheets (URL token)]
+    expected: FAIL
+
+  [Multiple (registered) var reference resolve against respective sheets (URL function)]
+    expected: FAIL
+
+  [Registered UTF16BE-encoded var reference resolve against sheet (URL token)]
+    expected: FAIL
+
+  [Registered UTF16BE-encoded var reference resolve against sheet (URL function)]
+    expected: FAIL

testing/web-platform/meta/css/css-properties-values-api/var-reference-registered-properties-cycles.html.ini

@@ -7,10 +7,3 @@
 
   [A var() cycle between a two unregistered properties is handled correctly.]
     expected: FAIL
-
-  [A var() cycle between a syntax:'*' property and an unregistered property is handled correctly.]
-    expected: FAIL
-
-  [Custom properties with universal syntax become guaranteed-invalid when invalid at computed-value time]
-    expected: FAIL
-

testing/web-platform/meta/css/css-properties-values-api/var-reference-registered-properties.html.ini

@@ -2,15 +2,6 @@
   [var() references work with registered properties]
     expected: FAIL
 
-  [Registered lists may be concatenated]
-    expected: FAIL
-
-  [References to mixed registered and unregistered var()-properties work in registered lists]
-    expected: FAIL
-
-  [References to registered var()-properties work in registered lists]
-    expected: FAIL
-
   [Calc expressions are resolved when substituting]
     expected: FAIL
 
@@ -20,18 +11,9 @@
   [Lists with relative units are absolutized when substituting]
     expected: FAIL
 
-  [Valid fallback does not invalidate var()-reference [<length> | <color>, red\]]
-    expected: FAIL
-
-  [Valid fallback does not invalidate var()-reference [<length>, 10px\]]
-    expected: FAIL
-
   [Invalid fallback invalidates var()-reference [<length>, red\]]
     expected: FAIL
 
-  [Valid fallback does not invalidate var()-reference [<length> | none, none\]]
-    expected: FAIL
-
   [Invalid fallback invalidates var()-reference [<length>, var(--novar)\]]
     expected: FAIL
 
@@ -40,4 +22,3 @@
 
   [Values are absolutized when substituting into properties with universal syntax]
     expected: FAIL
-