Have ContainerNodeAlgorithms deal with references instead of pointers

Source/core/svg/SVGElementInstance.h

Index: Source/core/svg/SVGElementInstance.h
diff --git a/Source/core/svg/SVGElementInstance.h b/Source/core/svg/SVGElementInstance.h
index d2a1784b35a122d2965a644d975d6b2333134d3b..66de33c7d7509e29e64d9a4e23fd3cea5490fdaa 100644
--- a/Source/core/svg/SVGElementInstance.h
+++ b/Source/core/svg/SVGElementInstance.h
@@ -29,7 +29,7 @@ namespace WebCore {
 
 namespace Private {
 template<class GenericNode, class GenericNodeContainer>
-void addChildNodesToDeletionQueue(GenericNode*& head, GenericNode*& tail, GenericNodeContainer* container);
+void addChildNodesToDeletionQueue(GenericNode*& head, GenericNode*& tail, GenericNodeContainer&);
 };
 
 class Document;
@@ -156,13 +156,13 @@ private:
     void setShadowTreeElement(SVGElement*);
 
     template<class GenericNode, class GenericNodeContainer>
-    friend void appendChildToContainer(GenericNode* child, GenericNodeContainer* container);
+    friend void appendChildToContainer(GenericNode& child, GenericNodeContainer&);
 
     template<class GenericNode, class GenericNodeContainer>
-    friend void removeDetachedChildrenInContainer(GenericNodeContainer*);
+    friend void removeDetachedChildrenInContainer(GenericNodeContainer&);
 
     template<class GenericNode, class GenericNodeContainer>
-    friend void Private::addChildNodesToDeletionQueue(GenericNode*& head, GenericNode*& tail, GenericNodeContainer* container);
+    friend void Private::addChildNodesToDeletionQueue(GenericNode*& head, GenericNode*& tail, GenericNodeContainer&);
 
     bool hasChildNodes() const { return m_firstChild; }