--- a/editor/libeditor/EditorBase.cpp
+++ b/editor/libeditor/EditorBase.cpp
@@ -3833,22 +3833,16 @@ EditorBase::IsDescendantOfEditorRoot(nsI
 
 bool
 EditorBase::IsContainer(nsINode* aNode)
 {
   return aNode ? true : false;
 }
 
 bool
-EditorBase::IsContainer(nsIDOMNode* aNode)
-{
-  return aNode ? true : false;
-}
-
-bool
 EditorBase::IsEditable(nsIDOMNode* aNode)
 {
   nsCOMPtr<nsIContent> content = do_QueryInterface(aNode);
   return IsEditable(content);
 }
 
 uint32_t
 EditorBase::CountEditableChildren(nsINode* aNode)

--- a/editor/libeditor/EditorBase.h
+++ b/editor/libeditor/EditorBase.h
@@ -953,17 +953,16 @@ public:
   bool IsDescendantOfRoot(nsIDOMNode* inNode);
   bool IsDescendantOfRoot(nsINode* inNode);
   bool IsDescendantOfEditorRoot(nsINode* aNode);
 
   /**
    * Returns true if aNode is a container.
    */
   virtual bool IsContainer(nsINode* aNode);
-  virtual bool IsContainer(nsIDOMNode* aNode);
 
   /**
    * returns true if aNode is an editable node.
    */
   bool IsEditable(nsIDOMNode* aNode);
   bool IsEditable(nsINode* aNode)
   {
     NS_ENSURE_TRUE(aNode, false);

--- a/editor/libeditor/HTMLEditor.cpp
+++ b/editor/libeditor/HTMLEditor.cpp
@@ -3458,27 +3458,16 @@ HTMLEditor::IsContainer(nsINode* aNode)
     tagEnum = eHTMLTag_text;
   } else {
     tagEnum = nsHTMLTags::StringTagToId(aNode->NodeName());
   }
 
   return HTMLEditUtils::IsContainer(tagEnum);
 }
 
-bool
-HTMLEditor::IsContainer(nsIDOMNode* aNode)
-{
-  nsCOMPtr<nsINode> node = do_QueryInterface(aNode);
-  if (!node) {
-    return false;
-  }
-  return IsContainer(node);
-}
-
-
 nsresult
 HTMLEditor::SelectEntireDocument(Selection* aSelection)
 {
   if (!aSelection || !mRules) {
     return NS_ERROR_NULL_POINTER;
   }
 
   // Protect the edit rules object from dying
@@ -4040,17 +4029,17 @@ HTMLEditor::IsEmptyNodeImpl(nsINode* aNo
   }
 
   // if it's not a text node (handled above) and it's not a container,
   // then we don't call it empty (it's an <hr>, or <br>, etc.).
   // Also, if it's an anchor then don't treat it as empty - even though
   // anchors are containers, named anchors are "empty" but we don't
   // want to treat them as such.  Also, don't call ListItems or table
   // cells empty if caller desires.  Form Widgets not empty.
-  if (!IsContainer(aNode->AsDOMNode()) ||
+  if (!IsContainer(aNode) ||
       (HTMLEditUtils::IsNamedAnchor(aNode) ||
        HTMLEditUtils::IsFormWidget(aNode) ||
        (aListOrCellNotEmpty &&
         (HTMLEditUtils::IsListItem(aNode) ||
          HTMLEditUtils::IsTableCell(aNode))))) {
     *outIsEmptyNode = false;
     return NS_OK;
   }

--- a/editor/libeditor/HTMLEditor.h
+++ b/editor/libeditor/HTMLEditor.h
@@ -294,17 +294,16 @@ public:
    */
   virtual bool TagCanContainTag(nsAtom& aParentTag,
                                 nsAtom& aChildTag) const override;
 
   /**
    * Returns true if aNode is a container.
    */
   virtual bool IsContainer(nsINode* aNode) override;
-  virtual bool IsContainer(nsIDOMNode* aNode) override;
 
   /**
    * Make the given selection span the entire document.
    */
   virtual nsresult SelectEntireDocument(Selection* aSelection) override;
 
   /**
    * Join together any adjacent editable text nodes in the range.