style: Remove some XBL code in the style system.

Differential Revision: https://phabricator.services.mozilla.com/D50554

components/selectors/context.rs

@@ -189,15 +189,6 @@ where
         }
     }
 
-    /// Override the quirks mode we're matching against.
-    ///
-    /// FIXME(emilio): This is a hack for XBL quirks-mode mismatches.
-    #[inline]
-    pub fn set_quirks_mode(&mut self, quirks_mode: QuirksMode) {
-        self.quirks_mode = quirks_mode;
-        self.classes_and_ids_case_sensitivity = quirks_mode.classes_and_ids_case_sensitivity();
-    }
-
     /// Whether we're matching a nested selector.
     #[inline]
     pub fn is_nested(&self) -> bool {

components/style/Cargo.toml

@@ -25,7 +25,6 @@ servo-layout-2020 = []
 gecko_debug = []
 gecko_refcount_logging = []
 gecko_profiler = []
-moz_xbl = []
 
 [dependencies]
 app_units = "0.7"

components/style/dom.rs

@@ -776,14 +776,6 @@ pub trait TElement:
         return data.hint.has_animation_hint();
     }
 
-    /// Returns the anonymous content for the current element's XBL binding,
-    /// given if any.
-    ///
-    /// This is used in Gecko for XBL.
-    fn xbl_binding_anonymous_content(&self) -> Option<Self::ConcreteNode> {
-        None
-    }
-
     /// The shadow root this element is a host of.
     fn shadow_root(&self) -> Option<<Self::ConcreteNode as TNode>::ConcreteShadowRoot>;
 

components/style/gecko/wrapper.rs

@@ -44,8 +44,6 @@ use crate::gecko_bindings::bindings::{Gecko_ElementState, Gecko_GetDocumentLWThe
 use crate::gecko_bindings::bindings::{Gecko_SetNodeFlags, Gecko_UnsetNodeFlags};
 use crate::gecko_bindings::structs;
 use crate::gecko_bindings::structs::nsChangeHint;
-#[cfg(feature = "moz_xbl")]
-use crate::gecko_bindings::structs::nsXBLBinding as RawGeckoXBLBinding;
 use crate::gecko_bindings::structs::Document_DocumentTheme as DocumentTheme;
 use crate::gecko_bindings::structs::EffectCompositor_CascadeLevel as CascadeLevel;
 use crate::gecko_bindings::structs::ELEMENT_HANDLED_SNAPSHOT;
@@ -86,8 +84,6 @@ use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::mem;
 use std::ptr;
-#[cfg(not(feature = "moz_xbl"))]
-use values::Impossible;
 
 #[inline]
 fn elements_with_id<'a, 'le>(
@@ -317,7 +313,7 @@ impl<'ln> GeckoNode<'ln> {
         }
 
         if let Some(parent) = parent_el {
-            if parent.shadow_root().is_some() || parent.xbl_binding().is_some() {
+            if parent.shadow_root().is_some() {
                 return false;
             }
         }
@@ -530,52 +526,6 @@ impl<'a> Iterator for GeckoChildrenIterator<'a> {
     }
 }
 
-/// A Simple wrapper over a non-null Gecko `nsXBLBinding` pointer.
-#[cfg(feature = "moz_xbl")]
-#[derive(Clone, Copy)]
-pub struct GeckoXBLBinding<'lb>(pub &'lb RawGeckoXBLBinding);
-
-#[cfg(feature = "moz_xbl")]
-impl<'lb> GeckoXBLBinding<'lb> {
-    #[inline]
-    fn base_binding(&self) -> Option<Self> {
-        unsafe { self.0.mNextBinding.mRawPtr.as_ref().map(GeckoXBLBinding) }
-    }
-
-    #[inline]
-    fn anon_content(&self) -> *const nsIContent {
-        self.0.mContent.raw::<nsIContent>()
-    }
-
-    // This duplicates the logic in Gecko's
-    // nsBindingManager::GetBindingWithContent.
-    fn binding_with_content(&self) -> Option<Self> {
-        let mut binding = *self;
-        loop {
-            if !binding.anon_content().is_null() {
-                return Some(binding);
-            }
-            binding = binding.base_binding()?;
-        }
-    }
-}
-
-/// A stub wraper for GeckoXBLBinding.
-#[cfg(not(feature = "moz_xbl"))]
-pub struct GeckoXBLBinding<'lb>(&'lb Impossible);
-
-#[cfg(not(feature = "moz_xbl"))]
-impl<'lb> GeckoXBLBinding<'lb> {
-    #[inline]
-    fn anon_content(&self) -> *const nsIContent {
-        match *self.0 {}
-    }
-
-    fn binding_with_content(&self) -> Option<Self> {
-        None
-    }
-}
-
 /// A simple wrapper over a non-null Gecko `Element` pointer.
 #[derive(Clone, Copy)]
 pub struct GeckoElement<'le>(pub &'le RawGeckoElement);
@@ -701,39 +651,6 @@ impl<'le> GeckoElement<'le> {
         })
     }
 
-    #[cfg(feature = "moz_xbl")]
-    #[inline]
-    fn may_be_in_binding_manager(&self) -> bool {
-        self.flags() & (structs::NODE_MAY_BE_IN_BINDING_MNGR as u32) != 0
-    }
-
-    #[cfg(feature = "moz_xbl")]
-    #[inline]
-    fn xbl_binding(&self) -> Option<GeckoXBLBinding<'le>> {
-        if !self.may_be_in_binding_manager() {
-            return None;
-        }
-
-        let slots = self.extended_slots()?;
-        unsafe { slots.mXBLBinding.mRawPtr.as_ref().map(GeckoXBLBinding) }
-    }
-
-    #[cfg(not(feature = "moz_xbl"))]
-    #[inline]
-    fn xbl_binding(&self) -> Option<GeckoXBLBinding<'le>> {
-        None
-    }
-
-    #[inline]
-    fn xbl_binding_with_content(&self) -> Option<GeckoXBLBinding<'le>> {
-        self.xbl_binding().and_then(|b| b.binding_with_content())
-    }
-
-    #[inline]
-    fn has_xbl_binding_with_content(&self) -> bool {
-        !self.xbl_binding_with_content().is_none()
-    }
-
     #[inline]
     fn namespace_id(&self) -> i32 {
         self.as_node().node_info().mInner.mNamespaceID
@@ -1107,9 +1024,8 @@ impl<'le> TElement for GeckoElement<'le> {
         // This condition is similar to the check that
         // StyleChildrenIterator::IsNeeded does, except that it might return
         // true if we used to (but no longer) have anonymous content from
-        // ::before/::after, XBL bindings, or nsIAnonymousContentCreators.
+        // ::before/::after, or nsIAnonymousContentCreators.
         if self.is_in_anonymous_subtree() ||
-            self.has_xbl_binding_with_content() ||
             self.is_html_slot_element() ||
             self.shadow_root().is_some() ||
             self.may_have_anonymous_children()
@@ -1595,11 +1511,6 @@ impl<'le> TElement for GeckoElement<'le> {
         self.may_have_animations() && unsafe { Gecko_ElementHasCSSTransitions(self.0) }
     }
 
-    fn xbl_binding_anonymous_content(&self) -> Option<GeckoNode<'le>> {
-        self.xbl_binding_with_content()
-            .map(|b| unsafe { GeckoNode::from_content(&*b.anon_content()) })
-    }
-
     fn might_need_transitions_update(
         &self,
         old_style: Option<&ComputedValues>,

components/style/invalidation/element/document_state.rs

@@ -31,9 +31,6 @@ impl Default for InvalidationMatchingData {
 /// An invalidation processor for style changes due to state and attribute
 /// changes.
 pub struct DocumentStateInvalidationProcessor<'a, E: TElement, I> {
-    // TODO(emilio): We might want to just run everything for every possible
-    // binding along with the document data, or just apply the XBL stuff to the
-    // bound subtrees.
     rules: I,
     matching_context: MatchingContext<'a, E::Impl>,
     document_states_changed: DocumentState,

components/style/invalidation/element/invalidator.rs

@@ -28,7 +28,7 @@ where
 
     /// Whether the invalidation processor only cares about light-tree
     /// descendants of a given element, that is, doesn't invalidate
-    /// pseudo-elements, NAC, or XBL anon content.
+    /// pseudo-elements, NAC, shadow dom...
     fn light_tree_only(&self) -> bool {
         false
     }
@@ -455,11 +455,6 @@ where
 
         let mut sibling_invalidations = InvalidationVector::new();
         for child in parent.dom_children() {
-            // TODO(emilio): We handle <xbl:children> fine, because they appear
-            // in selector-matching (note bug 1374247, though).
-            //
-            // This probably needs a shadow root check on `child` here, and
-            // recursing if that's the case.
             let child = match child.as_element() {
                 Some(e) => e,
                 None => continue,
@@ -574,13 +569,6 @@ where
             any_descendant |= self.invalidate_dom_descendants_of(root.as_node(), invalidations);
         }
 
-        // This is needed for XBL (technically) unconditionally, because XBL
-        // bindings do not block combinators in any way. However this is kinda
-        // broken anyway, since we should be looking at XBL rules too.
-        if let Some(anon_content) = self.element.xbl_binding_anonymous_content() {
-            any_descendant |= self.invalidate_dom_descendants_of(anon_content, invalidations);
-        }
-
         if let Some(marker) = self.element.marker_pseudo_element() {
             any_descendant |= self.invalidate_pseudo_element_or_nac(marker, invalidations);
         }