Further changes required by Servo

components/malloc_size_of/lib.rs

@@ -695,9 +695,9 @@ where
             Component::Slotted(ref selector) | Component::Host(Some(ref selector)) => {
                 selector.size_of(ops)
             },
-            Component::Is(ref list) |
+            Component::Is(ref list) | Component::Where(ref list) | Component::Has(ref list) => {
-            Component::Where(ref list) |
+                list.size_of(ops)
-            Component::Has(ref list) => list.size_of(ops),
+            },
             Component::PseudoElement(ref pseudo) => (*pseudo).size_of(ops),
             Component::Combinator(..) |
             Component::ExplicitAnyNamespace |

components/script/dom/element.rs

@@ -3178,6 +3178,10 @@ impl<'a> SelectorsElement for DomRoot<Element> {
             .next()
     }
 
+    fn first_element_child(&self) -> Option<DomRoot<Element>> {
+        self.GetFirstElementChild()
+    }
+
     fn attr_matches(
         &self,
         ns: &NamespaceConstraint<&style::Namespace>,

components/script/layout_dom/element.rs

@@ -506,6 +506,12 @@ impl<'dom, LayoutDataType: LayoutDataTrait> ::selectors::Element
         None
     }
 
+    fn first_element_child(&self) -> Option<Self> {
+        self.as_node()
+            .dom_children()
+            .find_map(|child| child.as_element())
+    }
+
     fn attr_matches(
         &self,
         ns: &NamespaceConstraint<&style::Namespace>,
@@ -801,6 +807,12 @@ impl<'dom, LayoutDataType: LayoutDataTrait> ::selectors::Element
         None
     }
 
+    // Skips non-element nodes
+    fn first_element_child(&self) -> Option<Self> {
+        warn!("ServoThreadSafeLayoutElement::first_element_child called");
+        None
+    }
+
     fn is_html_slot_element(&self) -> bool {
         self.element.is_html_slot_element()
     }