--- a/editor/libeditor/EditorBase.cpp
+++ b/editor/libeditor/EditorBase.cpp
@@ -69,17 +69,16 @@
 #include "nsFocusManager.h"             // for nsFocusManager
 #include "nsFrameSelection.h"           // for nsFrameSelection
 #include "nsGenericHTMLElement.h"       // for nsGenericHTMLElement
 #include "nsGkAtoms.h"                  // for nsGkAtoms, nsGkAtoms::dir
 #include "nsIAbsorbingTransaction.h"    // for nsIAbsorbingTransaction
 #include "nsAtom.h"                    // for nsAtom
 #include "nsIContent.h"                 // for nsIContent
 #include "nsIDocument.h"                // for nsIDocument
-#include "nsIDOMDocument.h"             // for nsIDOMDocument
 #include "nsIDOMEventListener.h"        // for nsIDOMEventListener
 #include "nsIDOMNode.h"                 // for nsIDOMNode, etc.
 #include "nsIDocumentStateListener.h"   // for nsIDocumentStateListener
 #include "nsIEditActionListener.h"      // for nsIEditActionListener
 #include "nsIEditorObserver.h"          // for nsIEditorObserver
 #include "nsIEditorSpellCheck.h"        // for nsIEditorSpellCheck
 #include "nsIFrame.h"                   // for nsIFrame
 #include "nsIHTMLDocument.h"            // for nsIHTMLDocument
@@ -649,27 +648,20 @@ EditorBase::GetIsDocumentEditable(bool* 
 {
   NS_ENSURE_ARG_POINTER(aIsDocumentEditable);
   nsCOMPtr<nsIDocument> doc = GetDocument();
   *aIsDocumentEditable = doc && IsModifiable();
 
   return NS_OK;
 }
 
-already_AddRefed<nsIDOMDocument>
-EditorBase::GetDOMDocument()
-{
-  nsCOMPtr<nsIDOMDocument> domDocument = do_QueryInterface(mDocument);
-  return domDocument.forget();
-}
-
 NS_IMETHODIMP
-EditorBase::GetDocument(nsIDOMDocument** aDoc)
-{
-  *aDoc = GetDOMDocument().take();
+EditorBase::GetDocument(nsIDocument** aDoc)
+{
+  NS_IF_ADDREF(*aDoc = mDocument);
   return *aDoc ? NS_OK : NS_ERROR_NOT_INITIALIZED;
 }
 
 already_AddRefed<nsIWidget>
 EditorBase::GetWidget()
 {
   nsCOMPtr<nsIPresShell> ps = GetPresShell();
   NS_ENSURE_TRUE(ps, nullptr);

--- a/editor/libeditor/EditorBase.h
+++ b/editor/libeditor/EditorBase.h
@@ -34,17 +34,16 @@
 #include "nsString.h"                   // for nsCString
 #include "nsTArray.h"                   // for nsTArray and nsAutoTArray
 #include "nsWeakReference.h"            // for nsSupportsWeakReference
 #include "nscore.h"                     // for nsresult, nsAString, etc.
 
 class mozInlineSpellChecker;
 class nsAtom;
 class nsIContent;
-class nsIDOMDocument;
 class nsIDOMNode;
 class nsIDocumentStateListener;
 class nsIEditActionListener;
 class nsIEditorObserver;
 class nsINode;
 class nsIPresShell;
 class nsISupports;
 class nsITransaction;
@@ -234,17 +233,16 @@ public:
    */
   virtual nsresult Init(nsIDocument& doc,
                         Element* aRoot,
                         nsISelectionController* aSelCon,
                         uint32_t aFlags,
                         const nsAString& aInitialValue);
 
   bool IsInitialized() const { return !!mDocument; }
-  already_AddRefed<nsIDOMDocument> GetDOMDocument();
   nsIDocument* GetDocument() const { return mDocument; }
   nsIPresShell* GetPresShell() const
   {
     return mDocument ? mDocument->GetShell() : nullptr;
   }
   nsPresContext* GetPresContext() const
   {
     nsIPresShell* presShell = GetPresShell();

--- a/editor/libeditor/HTMLEditor.cpp
+++ b/editor/libeditor/HTMLEditor.cpp
@@ -22,17 +22,16 @@
 #include "HTMLEditRules.h"
 #include "HTMLEditUtils.h"
 #include "HTMLURIRefObject.h"
 #include "StyleSheetTransactions.h"
 #include "TextEditUtils.h"
 #include "TypeInState.h"
 
 #include "nsHTMLDocument.h"
-#include "nsIDOMDocument.h"
 #include "nsIDocumentInlines.h"
 #include "nsISelectionController.h"
 #include "nsILinkHandler.h"
 #include "nsIInlineSpellChecker.h"
 
 #include "mozilla/css/Loader.h"
 
 #include "nsIContent.h"

--- a/editor/libeditor/HTMLEditor.h
+++ b/editor/libeditor/HTMLEditor.h
@@ -33,17 +33,16 @@
 #include "nsPoint.h"
 #include "nsStubMutationObserver.h"
 #include "nsTArray.h"
 
 class nsDocumentFragment;
 class nsHTMLDocument;
 class nsITransferable;
 class nsIClipboard;
-class nsIDOMDocument;
 class nsILinkHandler;
 class nsTableWrapperFrame;
 class nsIDOMRange;
 class nsRange;
 
 namespace mozilla {
 class AutoSelectionSetterAfterTableEdit;
 class HTMLEditorEventListener;

--- a/editor/libeditor/HTMLEditorDataTransfer.cpp
+++ b/editor/libeditor/HTMLEditorDataTransfer.cpp
@@ -33,17 +33,16 @@
 #include "nsIScriptError.h"
 #include "nsContentUtils.h"
 #include "nsDebug.h"
 #include "nsDependentSubstring.h"
 #include "nsError.h"
 #include "nsGkAtoms.h"
 #include "nsIClipboard.h"
 #include "nsIContent.h"
-#include "nsIDOMDocument.h"
 #include "nsIDOMNode.h"
 #include "nsIDocument.h"
 #include "nsIFile.h"
 #include "nsIInputStream.h"
 #include "nsIMIMEService.h"
 #include "nsNameSpaceManager.h"
 #include "nsINode.h"
 #include "nsIParserUtils.h"
@@ -172,25 +171,24 @@ HTMLEditor::InsertHTML(const nsAString& 
                                  nullptr,  nullptr, 0, true, true, false);
 }
 
 NS_IMETHODIMP
 HTMLEditor::InsertHTMLWithContext(const nsAString& aInputString,
                                   const nsAString& aContextStr,
                                   const nsAString& aInfoStr,
                                   const nsAString& aFlavor,
-                                  nsIDOMDocument* aSourceDoc,
+                                  nsIDocument* aSourceDoc,
                                   nsIDOMNode* aDestNode,
                                   int32_t aDestOffset,
                                   bool aDeleteSelection)
 {
-  nsCOMPtr<nsIDocument> sourceDoc = do_QueryInterface(aSourceDoc);
   nsCOMPtr<nsINode> destNode = do_QueryInterface(aDestNode);
   return DoInsertHTMLWithContext(aInputString, aContextStr, aInfoStr,
-                                 aFlavor, sourceDoc, destNode, aDestOffset,
+                                 aFlavor, aSourceDoc, destNode, aDestOffset,
                                  aDeleteSelection,
                                  /* trusted input */ true,
                                  /* clear style */ false);
 }
 
 nsresult
 HTMLEditor::DoInsertHTMLWithContext(const nsAString& aInputString,
                                     const nsAString& aContextStr,

--- a/editor/nsIEditor.idl
+++ b/editor/nsIEditor.idl
@@ -14,16 +14,17 @@ interface nsIDocumentStateListener;
 interface nsIOutputStream;
 interface nsITransactionManager;
 interface nsITransaction;
 interface nsIEditorObserver;
 interface nsIEditActionListener;
 interface nsIInlineSpellChecker;
 interface nsITransferable;
 
+webidl Document;
 webidl Element;
 webidl Selection;
 
 %{C++
 namespace mozilla {
 class EditorBase;
 class HTMLEditor;
 class TextEditor;
@@ -79,17 +80,17 @@ interface nsIEditor  : nsISupports
   readonly attribute boolean isDocumentEditable;
 
   /** Returns true if the current selection anchor is editable */
   readonly attribute boolean isSelectionEditable;
 
   /**
    * the DOM Document this editor is associated with, refcounted.
    */
-  readonly attribute nsIDOMDocument document;
+  readonly attribute Document document;
 
   /** the body element, i.e. the root of the editable document.
    */
   readonly attribute Element rootElement;
 
   /**
    * the selection controller for the current presentation, refcounted.
    */

--- a/editor/nsIHTMLEditor.idl
+++ b/editor/nsIHTMLEditor.idl
@@ -4,16 +4,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "nsISupports.idl"
 #include "domstubs.idl"
 
 interface nsIContent;
 interface nsIArray;
 
+webidl Document;
 webidl Element;
 webidl Node;
 webidl Selection;
 
 [scriptable, builtinclass, uuid(87ee993e-985f-4a43-a974-0d9512da2fb0)]
 interface nsIHTMLEditor : nsISupports
 {
 %{C++
@@ -164,17 +165,17 @@ interface nsIHTMLEditor : nsISupports
    * @param aDestinationOffset  used with aDestNode to determine insert location
    * @param aDeleteSelection    used with aDestNode during drag&drop
    * @param aCollapseSelection  used with aDestNode during drag&drop
    */
   void insertHTMLWithContext(in AString aInputString,
                              in AString aContextStr,
                              in AString aInfoStr,
                              in AString aFlavor,
-                             in nsIDOMDocument aSourceDoc,
+                             in Document aSourceDoc,
                              in nsIDOMNode aDestinationNode,
                              in long aDestinationOffset,
                              in boolean aDeleteSelection);
 
 
   /**
     * Insert an element, which may have child nodes, at the selection
     * Used primarily to insert a new element for various insert element dialogs,