Have NodeTraversal::nextSkippingChildren() take a reference

Source/core/css/StyleInvalidationAnalysis.cpp

Index: Source/core/css/StyleInvalidationAnalysis.cpp
diff --git a/Source/core/css/StyleInvalidationAnalysis.cpp b/Source/core/css/StyleInvalidationAnalysis.cpp
index 9fe923eb3e55d7743f4198a9b66b8f66cdd62a07..1bc0b5021a29513a7ed436a2ce771d766e61dc61 100644
--- a/Source/core/css/StyleInvalidationAnalysis.cpp
+++ b/Source/core/css/StyleInvalidationAnalysis.cpp
@@ -220,7 +220,7 @@ void StyleInvalidationAnalysis::invalidateStyle(Document* document)
         if (elementMatchesSelectorScopes(element, m_idScopes, m_classScopes)) {
             element->setNeedsStyleRecalc();
             // The whole subtree is now invalidated, we can skip to the next sibling.
-            element = ElementTraversal::nextSkippingChildren(element);
+            element = ElementTraversal::nextSkippingChildren(*element);
             continue;
         }
         element = ElementTraversal::next(*element);