Auto merge of #20243 - emilio:host-selector-on-the-way, r=SimonSapin

style: add infrastructure to match the :host selector.

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1 files changed, 8 insertions, 1 deletions

diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 5060492160b..a53446fd4a3 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -2570,6 +2570,14 @@ impl<'a> SelectorsElement for DomRoot<Element> {
         self.upcast::<Node>().GetParentElement()
     }
 
+    fn parent_node_is_shadow_root(&self) -> bool {
+        false
+    }
+
+    fn containing_shadow_host(&self) -> Option<Self> {
+        None
+    }
+
     fn match_pseudo_element(
         &self,
         _pseudo: &PseudoElement,
@@ -2578,7 +2586,6 @@ impl<'a> SelectorsElement for DomRoot<Element> {
         false
     }
 
-
     fn first_child_element(&self) -> Option<DomRoot<Element>> {
         self.node.child_elements().next()
     }