1 files changed, 14 insertions, 0 deletions
diff --git a/components/style/dom.rs b/components/style/dom.rs
index ea438b66dd9..85f4f49c4b7 100644
--- a/components/style/dom.rs
+++ b/components/style/dom.rs
@@ -416,6 +416,20 @@ pub trait TElement
         F: FnMut(Self),
     {}
 
+    /// Return whether this element is an element in the HTML namespace.
+    fn is_html_element(&self) -> bool;
+
+    /// Returns whether this element is a <html:slot> element.
+    fn is_html_slot_element(&self) -> bool {
+        self.get_local_name() == &*local_name!("slot") &&
+        self.is_html_element()
+    }
+
+    /// Return the list of slotted nodes of this node.
+    fn slotted_nodes(&self) -> &[Self::ConcreteNode] {
+        &[]
+    }
+
     /// For a given NAC element, return the closest non-NAC ancestor, which is
     /// guaranteed to exist.
     fn closest_non_native_anonymous_ancestor(&self) -> Option<Self> {