diff --git a/editor/libeditor/nsEditor.cpp b/editor/libeditor/nsEditor.cpp
index 05f65582d76e..f1edc2cc95dc 100644
--- a/editor/libeditor/nsEditor.cpp
+++ b/editor/libeditor/nsEditor.cpp
@@ -2882,25 +2882,6 @@ nsEditor::GetLengthOfDOMNode(nsIDOMNode *aNode, uint32_t &aCount)
 }
 
 
-nsresult 
-nsEditor::GetPriorNode(nsIDOMNode  *aParentNode, 
-                       int32_t      aOffset, 
-                       bool         aEditableNode, 
-                       nsCOMPtr<nsIDOMNode> *aResultNode,
-                       bool         bNoBlockCrossing)
-{
-  NS_ENSURE_TRUE(aResultNode, NS_ERROR_NULL_POINTER);
-  *aResultNode = nullptr;
-
-  nsCOMPtr<nsINode> parentNode = do_QueryInterface(aParentNode);
-  NS_ENSURE_TRUE(parentNode, NS_ERROR_NULL_POINTER);
-
-  *aResultNode = do_QueryInterface(GetPriorNode(parentNode, aOffset,
-                                                aEditableNode,
-                                                bNoBlockCrossing));
-  return NS_OK;
-}
-
 nsIContent*
 nsEditor::GetPriorNode(nsINode* aParentNode,
                        int32_t aOffset,
@@ -2936,25 +2917,6 @@ nsEditor::GetPriorNode(nsINode* aParentNode,
 }
 
 
-nsresult 
-nsEditor::GetNextNode(nsIDOMNode   *aParentNode, 
-                      int32_t      aOffset, 
-                      bool         aEditableNode, 
-                      nsCOMPtr<nsIDOMNode> *aResultNode,
-                      bool         bNoBlockCrossing)
-{
-  NS_ENSURE_TRUE(aResultNode, NS_ERROR_NULL_POINTER);
-  *aResultNode = nullptr;
-
-  nsCOMPtr<nsINode> parentNode = do_QueryInterface(aParentNode);
-  NS_ENSURE_TRUE(parentNode, NS_ERROR_NULL_POINTER);
-
-  *aResultNode = do_QueryInterface(GetNextNode(parentNode, aOffset,
-                                               aEditableNode,
-                                               bNoBlockCrossing));
-  return NS_OK;
-}
-
 nsIContent*
 nsEditor::GetNextNode(nsINode* aParentNode,
                       int32_t aOffset,
@@ -3006,22 +2968,6 @@ nsEditor::GetNextNode(nsINode* aParentNode,
 }
 
 
-nsresult 
-nsEditor::GetPriorNode(nsIDOMNode  *aCurrentNode, 
-                       bool         aEditableNode, 
-                       nsCOMPtr<nsIDOMNode> *aResultNode,
-                       bool         bNoBlockCrossing)
-{
-  NS_ENSURE_TRUE(aResultNode, NS_ERROR_NULL_POINTER);
-
-  nsCOMPtr<nsINode> currentNode = do_QueryInterface(aCurrentNode);
-  NS_ENSURE_TRUE(currentNode, NS_ERROR_NULL_POINTER);
-
-  *aResultNode = do_QueryInterface(GetPriorNode(currentNode, aEditableNode,
-                                                bNoBlockCrossing));
-  return NS_OK;
-}
-
 nsIContent*
 nsEditor::GetPriorNode(nsINode* aCurrentNode, bool aEditableNode,
                        bool aNoBlockCrossing /* = false */)
@@ -3087,22 +3033,6 @@ nsEditor::FindNextLeafNode(nsINode  *aCurrentNode,
   return nullptr;
 }
 
-nsresult
-nsEditor::GetNextNode(nsIDOMNode* aCurrentNode,
-                      bool aEditableNode,
-                      nsCOMPtr<nsIDOMNode> *aResultNode,
-                      bool bNoBlockCrossing)
-{
-  nsCOMPtr<nsINode> currentNode = do_QueryInterface(aCurrentNode);
-  if (!currentNode || !aResultNode) {
-    return NS_ERROR_NULL_POINTER;
-  }
-
-  *aResultNode = do_QueryInterface(GetNextNode(currentNode, aEditableNode,
-                                               bNoBlockCrossing));
-  return NS_OK;
-}
-
 nsIContent*
 nsEditor::GetNextNode(nsINode* aCurrentNode,
                       bool aEditableNode,
diff --git a/editor/libeditor/nsEditor.h b/editor/libeditor/nsEditor.h
index eed7d819d84c..c944791ced84 100644
--- a/editor/libeditor/nsEditor.h
+++ b/editor/libeditor/nsEditor.h
@@ -497,19 +497,10 @@ public:
     *                       If there is no prior node, aResultNode will be nullptr.
     * @param bNoBlockCrossing If true, don't move across "block" nodes, whatever that means.
     */
-  nsresult GetPriorNode(nsIDOMNode  *aCurrentNode, 
-                        bool         aEditableNode,
-                        nsCOMPtr<nsIDOMNode> *aResultNode,
-                        bool         bNoBlockCrossing = false);
   nsIContent* GetPriorNode(nsINode* aCurrentNode, bool aEditableNode,
                            bool aNoBlockCrossing = false);
 
   // and another version that takes a {parent,offset} pair rather than a node
-  nsresult GetPriorNode(nsIDOMNode  *aParentNode, 
-                        int32_t      aOffset, 
-                        bool         aEditableNode, 
-                        nsCOMPtr<nsIDOMNode> *aResultNode,
-                        bool         bNoBlockCrossing = false);
   nsIContent* GetPriorNode(nsINode* aParentNode,
                            int32_t aOffset,
                            bool aEditableNode,
@@ -523,20 +514,11 @@ public:
     *                       skipping non-editable nodes if aEditableNode is true.
     *                       If there is no prior node, aResultNode will be nullptr.
     */
-  nsresult GetNextNode(nsIDOMNode  *aCurrentNode, 
-                       bool         aEditableNode,
-                       nsCOMPtr<nsIDOMNode> *aResultNode,
-                       bool         bNoBlockCrossing = false);
   nsIContent* GetNextNode(nsINode* aCurrentNode,
                           bool aEditableNode,
                           bool bNoBlockCrossing = false);
 
   // and another version that takes a {parent,offset} pair rather than a node
-  nsresult GetNextNode(nsIDOMNode  *aParentNode, 
-                       int32_t      aOffset, 
-                       bool         aEditableNode, 
-                       nsCOMPtr<nsIDOMNode> *aResultNode,
-                       bool         bNoBlockCrossing = false);
   nsIContent* GetNextNode(nsINode* aParentNode,
                           int32_t aOffset,
                           bool aEditableNode,
diff --git a/editor/libeditor/nsHTMLEditRules.cpp b/editor/libeditor/nsHTMLEditRules.cpp
index d21fc97f8cd3..c0d3fed67707 100644
--- a/editor/libeditor/nsHTMLEditRules.cpp
+++ b/editor/libeditor/nsHTMLEditRules.cpp
@@ -796,20 +796,21 @@ nsHTMLEditRules::GetAlignment(bool *aMixed, nsIHTMLEditor::EAlignment *aAlign)
   *aAlign = nsIHTMLEditor::eLeft;
 
   // get selection
-  nsCOMPtr<nsISelection>selection;
   NS_ENSURE_STATE(mHTMLEditor);  
-  nsresult res = mHTMLEditor->GetSelection(getter_AddRefs(selection));
-  NS_ENSURE_SUCCESS(res, res);
+  nsRefPtr<Selection> selection = mHTMLEditor->GetSelection();
+  NS_ENSURE_STATE(selection);
 
   // get selection location
   NS_ENSURE_STATE(mHTMLEditor);  
-  nsCOMPtr<nsIDOMElement> rootElem = do_QueryInterface(mHTMLEditor->GetRoot());
+  nsCOMPtr<Element> rootElem = mHTMLEditor->GetRoot();
   NS_ENSURE_TRUE(rootElem, NS_ERROR_FAILURE);
 
   int32_t offset, rootOffset;
-  nsCOMPtr<nsIDOMNode> parent = nsEditor::GetNodeLocation(rootElem, &rootOffset);
+  nsCOMPtr<nsINode> parent = nsEditor::GetNodeLocation(rootElem, &rootOffset);
   NS_ENSURE_STATE(mHTMLEditor);
-  res = mHTMLEditor->GetStartNodeAndOffset(selection, getter_AddRefs(parent), &offset);
+  nsresult res = mHTMLEditor->GetStartNodeAndOffset(selection,
+                                                    getter_AddRefs(parent),
+                                                    &offset);
   NS_ENSURE_SUCCESS(res, res);
 
   // is the selection collapsed?
@@ -817,7 +818,7 @@ nsHTMLEditRules::GetAlignment(bool *aMixed, nsIHTMLEditor::EAlignment *aAlign)
   if (selection->Collapsed()) {
     // if it is, we want to look at 'parent' and its ancestors
     // for divs with alignment on them
-    nodeToExamine = parent;
+    nodeToExamine = GetAsDOMNode(parent);
   }
   else if (!mHTMLEditor) {
     return NS_ERROR_UNEXPECTED;
@@ -825,12 +826,12 @@ nsHTMLEditRules::GetAlignment(bool *aMixed, nsIHTMLEditor::EAlignment *aAlign)
   else if (mHTMLEditor->IsTextNode(parent)) 
   {
     // if we are in a text node, then that is the node of interest
-    nodeToExamine = parent;
-  } else if (nsEditor::NodeIsType(parent, nsGkAtoms::html) &&
-             offset == rootOffset) {
+    nodeToExamine = GetAsDOMNode(parent);
+  } else if (parent->Tag() == nsGkAtoms::html && offset == rootOffset) {
     // if we have selected the body, let's look at the first editable node
     NS_ENSURE_STATE(mHTMLEditor);
-    mHTMLEditor->GetNextNode(parent, offset, true, address_of(nodeToExamine));
+    nodeToExamine =
+      GetAsDOMNode(mHTMLEditor->GetNextNode(parent, offset, true));
   }
   else
   {