Pass implementation object to supplemental classes by reference

Source/core/dom/ParentNode.h

Index: Source/core/dom/ParentNode.h
diff --git a/Source/core/dom/ParentNode.h b/Source/core/dom/ParentNode.h
index 45f146c0e8581b68958d572121397ba8421c0248..dda6a8afb7da6170f1c740b3dee34ec320dee0ef 100644
--- a/Source/core/dom/ParentNode.h
+++ b/Source/core/dom/ParentNode.h
@@ -38,28 +38,25 @@ namespace WebCore {
 
 class ParentNode {
 public:
-    static PassRefPtr<HTMLCollection> children(ContainerNode* node)
+    static PassRefPtr<HTMLCollection> children(ContainerNode& node)
     {
-        return node->children();
+        return node.children();
     }
 
-    static Element* firstElementChild(ContainerNode* node)
+    static Element* firstElementChild(ContainerNode& node)
     {
-        ASSERT(node);
-        return ElementTraversal::firstWithin(*node);
+        return ElementTraversal::firstWithin(node);
     }
 
-    static Element* lastElementChild(ContainerNode* node)
+    static Element* lastElementChild(ContainerNode& node)
     {
-        ASSERT(node);
-        return ElementTraversal::lastWithin(*node);
+        return ElementTraversal::lastWithin(node);
     }
 
-    static unsigned childElementCount(ContainerNode* node)
+    static unsigned childElementCount(ContainerNode& node)
     {
-        ASSERT(node);
         unsigned count = 0;
-        for (Element* child = ElementTraversal::firstWithin(*node); child; child = ElementTraversal::nextSibling(*child))
+        for (Element* child = ElementTraversal::firstWithin(node); child; child = ElementTraversal::nextSibling(*child))
             ++count;
         return count;
     }