style: Add support for the ::marker pseudo element on list items. Alias :-moz-list-bullet/number to that in the parser.

Bug: 205202
Reviewed-by: emilio

1 files changed, 3 insertions, 1 deletions

diff --git a/components/style/gecko/pseudo_element.rs b/components/style/gecko/pseudo_element.rs
index 8160ea2c9b8..c49277409e0 100644
--- a/components/style/gecko/pseudo_element.rs
+++ b/components/style/gecko/pseudo_element.rs
@@ -33,7 +33,7 @@ impl ::selectors::parser::PseudoElement for PseudoElement {
     fn valid_after_slotted(&self) -> bool {
         matches!(
             *self,
-            PseudoElement::Before | PseudoElement::After | PseudoElement::Placeholder
+            PseudoElement::Before | PseudoElement::After | PseudoElement::Marker | PseudoElement::Placeholder
         )
     }
 
@@ -180,6 +180,8 @@ impl PseudoElement {
     /// Whether this pseudo-element should actually exist if it has
     /// the given styles.
     pub fn should_exist(&self, style: &ComputedValues) -> bool {
+        debug_assert!(self.is_eager());
+
         if style.get_box().clone_display() == Display::None {
             return false;
         }