Use more references in ContainerNode code

Source/core/dom/Node.cpp

Index: Source/core/dom/Node.cpp
diff --git a/Source/core/dom/Node.cpp b/Source/core/dom/Node.cpp
index 19b0e0bb2dafaf892c15cce83479b17eb2fff873..8fdeee786c6043a4c3e045666c81a7e887394d20 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -917,16 +917,17 @@ bool Node::containsIncludingShadowDOM(const Node* node) const
     return false;
 }
 
-bool Node::containsIncludingHostElements(const Node* node) const
+bool Node::containsIncludingHostElements(const Node& node) const
 {
-    while (node) {
-        if (node == this)
+    const Node* current = &node;
+    do {
+        if (current == this)
             return true;
-        if (node->isDocumentFragment() && toDocumentFragment(node)->isTemplateContent())
-            node = static_cast<const TemplateContentDocumentFragment*>(node)->host();
+        if (current->isDocumentFragment() && toDocumentFragment(current)->isTemplateContent())
+            current = static_cast<const TemplateContentDocumentFragment*>(current)->host();
         else
-            node = node->parentOrShadowHostNode();
-    }
+            current = current->parentOrShadowHostNode();
+    } while (current);
     return false;
 }