Have getChildNodes() take a ContainerNode in argument

Source/core/dom/ContainerNode.cpp

Index: Source/core/dom/ContainerNode.cpp
diff --git a/Source/core/dom/ContainerNode.cpp b/Source/core/dom/ContainerNode.cpp
index 8c20d806aca347a6e5ae6344e7aec2aeadda5aa2..dec61172bc1d12b3b1666a6c89c0ce5a7531aab9 100644
--- a/Source/core/dom/ContainerNode.cpp
+++ b/Source/core/dom/ContainerNode.cpp
@@ -66,14 +66,15 @@ unsigned NoEventDispatchAssertion::s_count = 0;
 
 static void collectChildrenAndRemoveFromOldParent(Node& node, NodeVector& nodes, ExceptionState& exceptionState)
 {
-    if (!node.isDocumentFragment()) {
-        nodes.append(&node);
-        if (ContainerNode* oldParent = node.parentNode())
-            oldParent->removeChild(&node, exceptionState);
+    if (node.isDocumentFragment()) {
+        DocumentFragment& fragment = toDocumentFragment(node);
+        getChildNodes(fragment, nodes);
+        fragment.removeChildren();
         return;
     }
-    getChildNodes(node, nodes);
-    toContainerNode(node).removeChildren();
+    nodes.append(&node);
+    if (ContainerNode* oldParent = node.parentNode())
+        oldParent->removeChild(&node, exceptionState);
 }
 
 #if !ENABLE(OILPAN)