Auto merge of #21036 - emilio:gecko-sync, r=emilio

style: Sync changes from mozilla-central.

See each individual commit for details.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/21036)
<!-- Reviewable:end -->

components/script/dom/cssstyledeclaration.rs

@@ -253,7 +253,7 @@ impl CSSStyleDeclaration {
         self.owner.mutate_associated_block(|pdb, changed| {
             if value.is_empty() {
                 // Step 3
-                *changed = pdb.remove_property(&id);
+                *changed = pdb.remove_property(&id, |_| {});
                 return Ok(());
             }
 
@@ -365,7 +365,7 @@ impl CSSStyleDeclarationMethods for CSSStyleDeclaration {
         let mut string = String::new();
         self.owner.mutate_associated_block(|pdb, changed| {
             pdb.property_value_to_css(&id, &mut string).unwrap();
-            *changed = pdb.remove_property(&id);
+            *changed = pdb.remove_property(&id, |_| {});
         });
 
         // Step 6

components/selectors/builder.rs

@@ -36,6 +36,7 @@ use std::slice;
 /// (from left to right). Once the process is complete, callers should invoke
 /// build(), which transforms the contents of the SelectorBuilder into a heap-
 /// allocated Selector and leaves the builder in a drained state.
+#[derive(Debug)]
 pub struct SelectorBuilder<Impl: SelectorImpl> {
     /// The entire sequence of simple selectors, from left to right, without combinators.
     ///
@@ -104,7 +105,7 @@ impl<Impl: SelectorImpl> SelectorBuilder<Impl> {
         parsed_slotted: bool,
     ) -> ThinArc<SpecificityAndFlags, Component<Impl>> {
         // Compute the specificity and flags.
-        let mut spec = SpecificityAndFlags(specificity(self.simple_selectors.iter()));
+        let mut spec = SpecificityAndFlags(specificity(&*self, self.simple_selectors.iter()));
         if parsed_pseudo {
             spec.0 |= HAS_PSEUDO_BIT;
         }
@@ -268,25 +269,35 @@ impl From<Specificity> for u32 {
     }
 }
 
-fn specificity<Impl>(iter: slice::Iter<Component<Impl>>) -> u32
+fn specificity<Impl>(builder: &SelectorBuilder<Impl>, iter: slice::Iter<Component<Impl>>) -> u32
 where
     Impl: SelectorImpl,
 {
-    complex_selector_specificity(iter).into()
+    complex_selector_specificity(builder, iter).into()
 }
 
-fn complex_selector_specificity<Impl>(mut iter: slice::Iter<Component<Impl>>) -> Specificity
+fn complex_selector_specificity<Impl>(
+    builder: &SelectorBuilder<Impl>,
+    mut iter: slice::Iter<Component<Impl>>,
+) -> Specificity
 where
     Impl: SelectorImpl,
 {
     fn simple_selector_specificity<Impl>(
+        builder: &SelectorBuilder<Impl>,
         simple_selector: &Component<Impl>,
         specificity: &mut Specificity,
     ) where
         Impl: SelectorImpl,
     {
         match *simple_selector {
-            Component::Combinator(..) => unreachable!(),
+            Component::Combinator(ref combinator) => {
+                unreachable!(
+                    "Found combinator {:?} in simple selectors vector? {:?}",
+                    combinator,
+                    builder,
+                );
+            }
             // FIXME(emilio): Spec doesn't define any particular specificity for
             // ::slotted(), so apply the general rule for pseudos per:
             //
@@ -326,15 +337,15 @@ where
             },
             Component::Negation(ref negated) => {
                 for ss in negated.iter() {
-                    simple_selector_specificity(&ss, specificity);
+                    simple_selector_specificity(builder, &ss, specificity);
                 }
             },
         }
     }
 
     let mut specificity = Default::default();
     for simple_selector in &mut iter {
-        simple_selector_specificity(&simple_selector, &mut specificity);
+        simple_selector_specificity(builder, &simple_selector, &mut specificity);
     }
     specificity
 }

components/selectors/parser.rs

@@ -92,7 +92,7 @@ macro_rules! with_all_bounds {
         /// NB: We need Clone so that we can derive(Clone) on struct with that
         /// are parameterized on SelectorImpl. See
         /// <https://github.com/rust-lang/rust/issues/26925>
-        pub trait SelectorImpl: Clone + Sized + 'static {
+        pub trait SelectorImpl: Clone + Debug + Sized + 'static {
             type ExtraMatchingData: Sized + Default + 'static;
             type AttrValue: $($InSelector)*;
             type Identifier: $($InSelector)*;
@@ -544,10 +544,26 @@ impl<Impl: SelectorImpl> Selector<Impl> {
     }
 
     /// Whether this selector is a featureless :host selector, with no
-    /// combinators to the left.
+    /// combinators to the left, and optionally has a pseudo-element to the
+    /// right.
     #[inline]
-    pub fn is_featureless_host_selector(&self) -> bool {
-        self.iter().is_featureless_host_selector()
+    pub fn is_featureless_host_selector_or_pseudo_element(&self) -> bool {
+        let mut iter = self.iter();
+        if !self.has_pseudo_element() {
+            return iter.is_featureless_host_selector();
+        }
+
+        // Skip the pseudo-element.
+        for _ in &mut iter { }
+
+        match iter.next_sequence() {
+            None => return false,
+            Some(combinator) => {
+                debug_assert_eq!(combinator, Combinator::PseudoElement);
+            }
+        }
+
+        iter.is_featureless_host_selector()
     }
 
     /// Returns an iterator over this selector in matching order (right-to-left),

components/style/Cargo.toml

@@ -59,7 +59,7 @@ serde = {version = "1.0", optional = true, features = ["derive"]}
 servo_arc = { path = "../servo_arc" }
 servo_atoms = {path = "../atoms", optional = true}
 servo_config = {path = "../config", optional = true}
-smallbitvec = "2.1.0"
+smallbitvec = "2.1.1"
 smallvec = "0.6"
 string_cache = { version = "0.7", optional = true }
 style_derive = {path = "../style_derive"}

components/style/animation.rs

@@ -10,7 +10,7 @@ use context::SharedStyleContext;
 use dom::{OpaqueNode, TElement};
 use font_metrics::FontMetricsProvider;
 use properties::{self, CascadeFlags, ComputedValues, LonghandId};
-use properties::animated_properties::{AnimatedProperty, TransitionProperty};
+use properties::animated_properties::AnimatedProperty;
 use properties::longhands::animation_direction::computed_value::single_value::T as AnimationDirection;
 use properties::longhands::animation_play_state::computed_value::single_value::T as AnimationPlayState;
 use rule_tree::CascadeLevel;
@@ -20,6 +20,7 @@ use std::sync::mpsc::Sender;
 use stylesheets::keyframes_rule::{KeyframesAnimation, KeyframesStep, KeyframesStepValue};
 use timer::Timer;
 use values::computed::Time;
+use values::computed::box_::TransitionProperty;
 use values::computed::transform::TimingFunction;
 use values::generics::box_::AnimationIterationCount;
 use values::generics::transform::{StepPosition, TimingFunction as GenericTimingFunction};
@@ -303,7 +304,8 @@ impl PropertyAnimation {
         let duration = box_style.transition_duration_mod(transition_index);
 
         match transition_property {
-            TransitionProperty::Unsupported(_) => result,
+            TransitionProperty::Custom(..) |
+            TransitionProperty::Unsupported(..) => result,
             TransitionProperty::Shorthand(ref shorthand_id) => shorthand_id
                 .longhands()
                 .filter_map(|longhand| {

components/style/font_face.rs

@@ -323,7 +323,7 @@ macro_rules! is_descriptor_enabled {
     ("font-variation-settings") => {
         unsafe {
             use gecko_bindings::structs::mozilla;
-            mozilla::StaticPrefs_sVarCache_layout_css_font_variations_enabled
+            mozilla::StaticPrefs_sVarCache_layout_css_font_variations_enabled != 0
         }
     };
     ($name:tt) => {

components/style/gecko/wrapper.rs

@@ -67,7 +67,6 @@ use media_queries::Device;
 use properties::{ComputedValues, LonghandId};
 use properties::{Importance, PropertyDeclaration, PropertyDeclarationBlock};
 use properties::animated_properties::{AnimationValue, AnimationValueMap};
-use properties::animated_properties::TransitionProperty;
 use properties::style_structs::Font;
 use rule_tree::CascadeLevel as ServoCascadeLevel;
 use selector_parser::{AttrValue, Direction, PseudoClassStringArg};
@@ -181,7 +180,6 @@ impl<'lr> TShadowRoot for GeckoShadowRoot<'lr> {
 
         let author_styles = AuthorStyles::<GeckoStyleSheet>::from_ffi(author_styles);
 
-        debug_assert!(!author_styles.stylesheets.dirty());
         debug_assert!(
             author_styles.quirks_mode == self.as_node().owner_doc().quirks_mode() ||
                 author_styles.stylesheets.is_empty()
@@ -617,31 +615,37 @@ impl<'le> GeckoElement<'le> {
     // GeckoNode is a raw reference.
     //
     // We can use a Cell<T>, but that's a bit of a pain.
+    #[inline]
     fn set_flags(&self, flags: u32) {
         unsafe { Gecko_SetNodeFlags(self.as_node().0, flags) }
     }
 
+    #[inline]
     unsafe fn unset_flags(&self, flags: u32) {
         Gecko_UnsetNodeFlags(self.as_node().0, flags)
     }
 
     /// Returns true if this element has descendants for lazy frame construction.
+    #[inline]
     pub fn descendants_need_frames(&self) -> bool {
         self.flags() & (NODE_DESCENDANTS_NEED_FRAMES as u32) != 0
     }
 
     /// Returns true if this element needs lazy frame construction.
+    #[inline]
     pub fn needs_frame(&self) -> bool {
         self.flags() & (NODE_NEEDS_FRAME as u32) != 0
     }
 
     /// Returns a reference to the DOM slots for this Element, if they exist.
+    #[inline]
     fn dom_slots(&self) -> Option<&structs::FragmentOrElement_nsDOMSlots> {
         let slots = self.as_node().0.mSlots as *const structs::FragmentOrElement_nsDOMSlots;
         unsafe { slots.as_ref() }
     }
 
     /// Returns a reference to the extended DOM slots for this Element.
+    #[inline]
     fn extended_slots(&self) -> Option<&structs::FragmentOrElement_nsExtendedDOMSlots> {
         self.dom_slots().and_then(|s| unsafe {
             (s._base.mExtendedSlots.mPtr as *const structs::FragmentOrElement_nsExtendedDOMSlots)
@@ -699,6 +703,7 @@ impl<'le> GeckoElement<'le> {
         }
     }
 
+    #[inline]
     fn non_xul_xbl_binding_parent_raw_content(&self) -> *mut nsIContent {
         debug_assert!(!self.is_xul_element());
         self.extended_slots()
@@ -1113,7 +1118,23 @@ impl<'le> TElement for GeckoElement<'le> {
             assert_eq!(base as *const _, self.0 as *const _, "Bad cast");
         }
 
-        let assigned_nodes: &[structs::RefPtr<structs::nsINode>] = &*slot.mAssignedNodes;
+        // FIXME(emilio): Workaround a bindgen bug on Android that causes
+        // mAssignedNodes to be at the wrong offset. See bug 1466406.
+        //
+        // Bug 1466580 tracks running the Android layout tests on automation.
+        //
+        // The actual bindgen bug still needs reduction.
+        let assigned_nodes: &[structs::RefPtr<structs::nsINode>] =
+            if !cfg!(target_os = "android") {
+                debug_assert_eq!(
+                    unsafe { bindings::Gecko_GetAssignedNodes(self.0) },
+                    &slot.mAssignedNodes as *const _,
+                );
+
+                &*slot.mAssignedNodes
+            } else {
+                unsafe { &**bindings::Gecko_GetAssignedNodes(self.0) }
+            };
 
         debug_assert_eq!(
             mem::size_of::<structs::RefPtr<structs::nsINode>>(),
@@ -1351,6 +1372,7 @@ impl<'le> TElement for GeckoElement<'le> {
         !self.is_in_native_anonymous_subtree()
     }
 
+    #[inline]
     fn implemented_pseudo_element(&self) -> Option<PseudoElement> {
         if !self.is_in_native_anonymous_subtree() {
             return None;
@@ -1364,6 +1386,7 @@ impl<'le> TElement for GeckoElement<'le> {
         PseudoElement::from_pseudo_type(pseudo_type)
     }
 
+    #[inline]
     fn store_children_to_process(&self, _: isize) {
         // This is only used for bottom-up traversal, and is thus a no-op for Gecko.
     }
@@ -1587,6 +1610,7 @@ impl<'le> TElement for GeckoElement<'le> {
     ) -> bool {
         use gecko_bindings::structs::nsCSSPropertyID;
         use properties::LonghandIdSet;
+        use values::computed::TransitionProperty;
 
         debug_assert!(
             self.might_need_transitions_update(Some(before_change_style), after_change_style),
@@ -1630,6 +1654,7 @@ impl<'le> TElement for GeckoElement<'le> {
             };
 
             match transition_property {
+                TransitionProperty::Custom(..) |
                 TransitionProperty::Unsupported(..) => {},
                 TransitionProperty::Shorthand(ref shorthand) => {
                     if shorthand.longhands().any(property_check_helper) {

components/style/gecko_bindings/sugar/ns_compatibility.rs

@@ -8,6 +8,7 @@ use context::QuirksMode;
 use gecko_bindings::structs::nsCompatibility;
 
 impl From<nsCompatibility> for QuirksMode {
+    #[inline]
     fn from(mode: nsCompatibility) -> QuirksMode {
         match mode {
             nsCompatibility::eCompatibility_FullStandards => QuirksMode::NoQuirks,