Have HTMLFrameOwnerElement / SubframeLoadingDisabler deal with references

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 676aac1242c518514d9857dd75f1267b15c5a118..8e918c9c2dd99f208661be41cfc0b3247d0af2a0 100644
--- a/Source/core/dom/ContainerNode.cpp
+++ b/Source/core/dom/ContainerNode.cpp
@@ -540,7 +540,7 @@ void ContainerNode::removeChildren()
     {
         // Removing focus can cause frames to load, either via events (focusout, blur)
         // or widget updates (e.g., for <embed>).
-        SubframeLoadingDisabler disabler(this);
+        SubframeLoadingDisabler disabler(*this);
 
         // Exclude this node when looking for removed focusedElement since only
         // children will be removed.