Bug 1331047: Require a child iterator for elements with ::before and ::after pseudos. r=bholley

MozReview-Commit-ID: e1UTlnNn3X

dom/base/ChildIterator.cpp

@@ -512,6 +512,16 @@ StyleChildrenIterator::IsNeeded(const Element* aElement)
     }
   }
 
+  // If the node has a ::before or ::after pseudo, return true, because we want
+  // to visit those.
+  //
+  // TODO(emilio): Make this fast adding a bit? or, perhaps just using
+  // ProbePseudoElementStyle? It should be quite fast in Stylo.
+  if (aElement->GetProperty(nsGkAtoms::beforePseudoProperty) ||
+      aElement->GetProperty(nsGkAtoms::afterPseudoProperty)) {
+    return true;
+  }
+
   // If the node has native anonymous content, return true.
   nsIAnonymousContentCreator* ac = do_QueryFrame(aElement->GetPrimaryFrame());
   if (ac) {