--- a/editor/txtsvc/nsITextServicesDocument.h
+++ b/editor/txtsvc/nsITextServicesDocument.h
@@ -5,19 +5,19 @@
 
 #ifndef nsITextServicesDocument_h__
 #define nsITextServicesDocument_h__
 
 #include "nsISupports.h"
 #include "nsStringFwd.h"
 
 class nsIDOMDocument;
-class nsIDOMRange;
 class nsIEditor;
 class nsITextServicesFilter;
+class nsRange;
 
 /*
 TextServicesDocument interface to outside world
 */
 
 #define NS_ITEXTSERVICESDOCUMENT_IID            \
 { /* 019718E1-CDB5-11d2-8D3C-000000000000 */    \
 0x019718e1, 0xcdb5, 0x11d2,                     \
@@ -62,25 +62,25 @@ public:
    * Sets the range/extent over which the text services document
    * will iterate. Note that InitWithEditor() should have been called prior to
    * calling this method. If this method is never called, the text services
    * defaults to iterating over the entire document.
    *
    * @param aDOMRange is the range to use. aDOMRange must point to a
    * valid range object.
    */
-  NS_IMETHOD SetExtent(nsIDOMRange* aDOMRange) = 0;
+  NS_IMETHOD SetExtent(nsRange* aDOMRange) = 0;
 
   /**
    * Expands the end points of the range so that it spans complete words.
    * This call does not change any internal state of the text services document.
    *
    * @param aDOMRange the range to be expanded/adjusted.
    */
-  NS_IMETHOD ExpandRangeToWordBoundaries(nsIDOMRange *aRange) = 0;
+  NS_IMETHOD ExpandRangeToWordBoundaries(nsRange* aRange) = 0;
 
   /**
    * Sets the filter to be used while iterating over content.
    * @param aFilter filter to be used while iterating over content.
    */
   NS_IMETHOD SetFilter(nsITextServicesFilter *aFilter) = 0;
 
   /**

--- a/editor/txtsvc/nsTextServicesDocument.cpp
+++ b/editor/txtsvc/nsTextServicesDocument.cpp
@@ -17,17 +17,16 @@
 #include "nsIContent.h"                 // for nsIContent, etc
 #include "nsIContentIterator.h"         // for nsIContentIterator
 #include "nsID.h"                       // for NS_GET_IID
 #include "nsIDOMDocument.h"             // for nsIDOMDocument
 #include "nsIDOMElement.h"              // for nsIDOMElement
 #include "nsIDOMHTMLDocument.h"         // for nsIDOMHTMLDocument
 #include "nsIDOMHTMLElement.h"          // for nsIDOMHTMLElement
 #include "nsIDOMNode.h"                 // for nsIDOMNode, etc
-#include "nsIDOMRange.h"                // for nsIDOMRange, etc
 #include "nsIEditor.h"                  // for nsIEditor, etc
 #include "nsINode.h"                    // for nsINode
 #include "nsIPlaintextEditor.h"         // for nsIPlaintextEditor
 #include "nsISelection.h"               // for nsISelection
 #include "nsISelectionController.h"     // for nsISelectionController, etc
 #include "nsISupportsBase.h"            // for nsISupports
 #include "nsISupportsUtils.h"           // for NS_IF_ADDREF, NS_ADDREF, etc
 #include "nsITextServicesFilter.h"      // for nsITextServicesFilter
@@ -188,27 +187,27 @@ nsTextServicesDocument::GetDocument(nsID
 
   *aDoc = mDOMDocument;
   NS_ADDREF(*aDoc);
 
   return NS_OK;
 }
 
 NS_IMETHODIMP
-nsTextServicesDocument::SetExtent(nsIDOMRange* aDOMRange)
+nsTextServicesDocument::SetExtent(nsRange* aRange)
 {
-  NS_ENSURE_ARG_POINTER(aDOMRange);
+  NS_ENSURE_ARG_POINTER(aRange);
   NS_ENSURE_TRUE(mDOMDocument, NS_ERROR_FAILURE);
 
   LOCK_DOC(this);
 
   // We need to store a copy of aDOMRange since we don't
   // know where it came from.
 
-  mExtent = static_cast<nsRange*>(aDOMRange)->CloneRange();
+  mExtent = aRange->CloneRange();
 
   // Create a new iterator based on our new extent range.
 
   nsresult rv = CreateContentIterator(mExtent, getter_AddRefs(mIterator));
 
   if (NS_FAILED(rv)) {
     UNLOCK_DOC(this);
     return rv;
@@ -222,37 +221,36 @@ nsTextServicesDocument::SetExtent(nsIDOM
   rv = FirstBlock();
 
   UNLOCK_DOC(this);
 
   return rv;
 }
 
 NS_IMETHODIMP
-nsTextServicesDocument::ExpandRangeToWordBoundaries(nsIDOMRange *aRange)
+nsTextServicesDocument::ExpandRangeToWordBoundaries(nsRange* aRange)
 {
   NS_ENSURE_ARG_POINTER(aRange);
-  RefPtr<nsRange> range = static_cast<nsRange*>(aRange);
 
   // Get the end points of the range.
 
   nsCOMPtr<nsINode> rngStartNode, rngEndNode;
   int32_t rngStartOffset, rngEndOffset;
 
-  nsresult rv = GetRangeEndPoints(range, getter_AddRefs(rngStartNode),
+  nsresult rv = GetRangeEndPoints(aRange, getter_AddRefs(rngStartNode),
                                   &rngStartOffset,
                                   getter_AddRefs(rngEndNode),
                                   &rngEndOffset);
 
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Create a content iterator based on the range.
 
   nsCOMPtr<nsIContentIterator> iter;
-  rv = CreateContentIterator(range, getter_AddRefs(iter));
+  rv = CreateContentIterator(aRange, getter_AddRefs(iter));
 
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Find the first text node in the range.
 
   TSDIteratorStatus iterStatus;
 
   rv = FirstTextNode(iter, &iterStatus);
@@ -367,18 +365,18 @@ nsTextServicesDocument::ExpandRangeToWor
       rngEndOffset != wordStartOffset ||
       (rngEndNode == rngStartNode && rngEndOffset == rngStartOffset)) {
     rngEndNode = wordEndNode;
     rngEndOffset = wordEndOffset;
   }
 
   // Now adjust the range so that it uses our new
   // end points.
-  rv = range->SetStartAndEnd(rngStartNode, rngStartOffset,
-                             rngEndNode, rngEndOffset);
+  rv = aRange->SetStartAndEnd(rngStartNode, rngStartOffset,
+                              rngEndNode, rngEndOffset);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsTextServicesDocument::SetFilter(nsITextServicesFilter *aFilter)

--- a/editor/txtsvc/nsTextServicesDocument.h
+++ b/editor/txtsvc/nsTextServicesDocument.h
@@ -17,17 +17,16 @@
 #include "nscore.h"
 
 class OffsetEntry;
 class nsIContent;
 class nsIContentIterator;
 class nsIDOMCharacterData;
 class nsIDOMDocument;
 class nsIDOMNode;
-class nsIDOMRange;
 class nsIEditor;
 class nsISelection;
 class nsISelectionController;
 class nsITextServicesFilter;
 
 /** implementation of a text services object.
  *
  */
@@ -72,18 +71,18 @@ public:
 
   /* Macro for AddRef(), Release(), and QueryInterface() */
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsTextServicesDocument, nsITextServicesDocument)
 
   /* nsITextServicesDocument method implementations. */
   NS_IMETHOD InitWithEditor(nsIEditor *aEditor) override;
   NS_IMETHOD GetDocument(nsIDOMDocument **aDoc) override;
-  NS_IMETHOD SetExtent(nsIDOMRange* aDOMRange) override;
-  NS_IMETHOD ExpandRangeToWordBoundaries(nsIDOMRange *aRange) override;
+  NS_IMETHOD SetExtent(nsRange* aRange) override;
+  NS_IMETHOD ExpandRangeToWordBoundaries(nsRange* aRange) override;
   NS_IMETHOD SetFilter(nsITextServicesFilter *aFilter) override;
   NS_IMETHOD GetCurrentTextBlock(nsString *aStr) override;
   NS_IMETHOD FirstBlock() override;
   NS_IMETHOD LastSelectedBlock(TSDBlockSelectionStatus *aSelStatus, int32_t *aSelOffset, int32_t *aSelLength) override;
   NS_IMETHOD PrevBlock() override;
   NS_IMETHOD NextBlock() override;
   NS_IMETHOD IsDone(bool *aIsDone) override;
   NS_IMETHOD SetSelection(int32_t aOffset, int32_t aLength) override;