diff --git a/layout/base/nsFrameManager.h b/layout/base/nsFrameManager.h
index da11a5930845..5a129f7bfe9d 100644
--- a/layout/base/nsFrameManager.h
+++ b/layout/base/nsFrameManager.h
@@ -151,14 +151,6 @@ public:
                                    nsIAtom*        aListName,
                                    nsIFrame*       aOldFrame);
 
-  NS_HIDDEN_(nsresult) ReplaceFrame(nsIFrame*       aParentFrame,
-                                    nsIAtom*        aListName,
-                                    nsIFrame*       aOldFrame,
-                                    nsIFrame*       aNewFrame)
-  {
-    return aParentFrame->ReplaceFrame(aListName, aOldFrame, aNewFrame);
-  }
-
   /*
    * Notification that a frame is about to be destroyed. This allows any
    * outstanding references to the frame to be cleaned up.
diff --git a/layout/forms/nsFieldSetFrame.cpp b/layout/forms/nsFieldSetFrame.cpp
index 35cdcf3edb11..a27fe603c347 100644
--- a/layout/forms/nsFieldSetFrame.cpp
+++ b/layout/forms/nsFieldSetFrame.cpp
@@ -94,9 +94,6 @@ public:
                           nsIFrame*      aFrameList);
   NS_IMETHOD RemoveFrame(nsIAtom*       aListName,
                          nsIFrame*      aOldFrame);
-  NS_IMETHOD ReplaceFrame(nsIAtom*       aListName,
-                          nsIFrame*      aOldFrame,
-                          nsIFrame*      aNewFrame);
 
   virtual nsIFrame* GetFrameForPoint(const nsPoint&    aPoint,
                                      nsFramePaintLayer aWhichLayer);
@@ -647,18 +644,6 @@ nsFieldSetFrame::RemoveFrame(nsIAtom*       aListName,
   return mContentFrame->RemoveFrame(aListName, aOldFrame);
 }
 
-NS_IMETHODIMP
-nsFieldSetFrame::ReplaceFrame(nsIAtom*       aListName,
-                              nsIFrame*      aOldFrame,
-                              nsIFrame*      aNewFrame)
-{
-  if (aOldFrame == mLegendFrame) {
-    mLegendFrame = aNewFrame;
-    return nsContainerFrame::ReplaceFrame(aListName, aOldFrame, aNewFrame);
-  }
-  return mContentFrame->ReplaceFrame(aListName, aOldFrame, aNewFrame);
-}
-
 nsIFrame*
 nsFieldSetFrame::GetFrameForPoint(const nsPoint&    aPoint,
                                   nsFramePaintLayer aWhichLayer)
diff --git a/layout/forms/nsHTMLButtonControlFrame.cpp b/layout/forms/nsHTMLButtonControlFrame.cpp
index 0161cd18cecf..827d9827fe49 100644
--- a/layout/forms/nsHTMLButtonControlFrame.cpp
+++ b/layout/forms/nsHTMLButtonControlFrame.cpp
@@ -572,12 +572,3 @@ nsHTMLButtonControlFrame::RemoveFrame(nsIAtom*        aListName,
 {
   return mFrames.FirstChild()->RemoveFrame(aListName, aOldFrame);
 }
-
-NS_IMETHODIMP
-nsHTMLButtonControlFrame::ReplaceFrame(nsIAtom*        aListName,
-                                       nsIFrame*       aOldFrame,
-                                       nsIFrame*       aNewFrame)
-{
-  ReParentFrameList(GetPresContext()->FrameManager(), aNewFrame);
-  return mFrames.FirstChild()->ReplaceFrame(aListName, aOldFrame, aNewFrame);
-}
diff --git a/layout/forms/nsHTMLButtonControlFrame.h b/layout/forms/nsHTMLButtonControlFrame.h
index d908232604f5..964883492747 100644
--- a/layout/forms/nsHTMLButtonControlFrame.h
+++ b/layout/forms/nsHTMLButtonControlFrame.h
@@ -112,10 +112,6 @@ public:
   NS_IMETHOD RemoveFrame(nsIAtom*        aListName,
                          nsIFrame*       aOldFrame);
 
-  NS_IMETHOD ReplaceFrame(nsIAtom*        aListName,
-                          nsIFrame*       aOldFrame,
-                          nsIFrame*       aNewFrame);
-
 #ifdef ACCESSIBILITY
   NS_IMETHOD GetAccessible(nsIAccessible** aAccessible);
 #endif
diff --git a/layout/generic/nsAbsoluteContainingBlock.cpp b/layout/generic/nsAbsoluteContainingBlock.cpp
index e6626d282aa5..5307ac5788f8 100644
--- a/layout/generic/nsAbsoluteContainingBlock.cpp
+++ b/layout/generic/nsAbsoluteContainingBlock.cpp
@@ -122,18 +122,6 @@ nsAbsoluteContainingBlock::RemoveFrame(nsIFrame*       aDelegatingFrame,
   return result ? NS_OK : NS_ERROR_FAILURE;
 }
 
-nsresult
-nsAbsoluteContainingBlock::ReplaceFrame(nsIFrame*      aDelegatingFrame,
-                                        nsIAtom*       aListName,
-                                        nsIFrame*      aOldFrame,
-                                        nsIFrame*      aNewFrame)
-{
-  PRBool result = mAbsoluteFrames.ReplaceFrame(aDelegatingFrame,
-                                               aOldFrame, aNewFrame, PR_TRUE);
-  NS_ASSERTION(result, "Problems replacing a frame");
-  return result ? NS_OK : NS_ERROR_FAILURE;
-}
-
 static void
 AddFrameToChildBounds(nsIFrame* aKidFrame, nsRect* aChildBounds)
 {
diff --git a/layout/generic/nsAbsoluteContainingBlock.h b/layout/generic/nsAbsoluteContainingBlock.h
index 376115c63456..420027b6717e 100644
--- a/layout/generic/nsAbsoluteContainingBlock.h
+++ b/layout/generic/nsAbsoluteContainingBlock.h
@@ -83,10 +83,6 @@ public:
   nsresult RemoveFrame(nsIFrame*      aDelegatingFrame,
                        nsIAtom*       aListName,
                        nsIFrame*      aOldFrame);
-  nsresult ReplaceFrame(nsIFrame*      aDelegatingFrame,
-                        nsIAtom*       aListName,
-                        nsIFrame*      aOldFrame,
-                        nsIFrame*      aNewFrame);
 
   // Called by the delegating frame after it has done its reflow first. This
   // function will reflow any absolutely positioned child frames that need to
diff --git a/layout/generic/nsContainerFrame.cpp b/layout/generic/nsContainerFrame.cpp
index c621ff7a886f..5544e1c23976 100644
--- a/layout/generic/nsContainerFrame.cpp
+++ b/layout/generic/nsContainerFrame.cpp
@@ -349,28 +349,6 @@ nsContainerFrame::GetFrameForPointUsing(const nsPoint& aPoint,
   return nsnull;
 }
 
-NS_IMETHODIMP
-nsContainerFrame::ReplaceFrame(nsIAtom*        aListName,
-                               nsIFrame*       aOldFrame,
-                               nsIFrame*       aNewFrame)
-{
-  nsIFrame* prevFrame;
-  nsresult  rv;
-
-  // Get the old frame's previous sibling frame
-  nsFrameList frames(GetFirstChild(aListName));
-  NS_ASSERTION(frames.ContainsFrame(aOldFrame), "frame is not a valid child frame");
-  prevFrame = frames.GetPrevSiblingFor(aOldFrame);
-
-  // Default implementation treats it like two separate operations
-  rv = RemoveFrame(aListName, aOldFrame);
-  if (NS_SUCCEEDED(rv)) {
-    rv = InsertFrames(aListName, prevFrame, aNewFrame);
-  }
-
-  return rv;
-}
-
 NS_IMETHODIMP
 nsContainerFrame::ReflowDirtyChild(nsIPresShell* aPresShell, nsIFrame* aChild)
 {
diff --git a/layout/generic/nsContainerFrame.h b/layout/generic/nsContainerFrame.h
index 431bacc1b9a7..ffa5a433fa9f 100644
--- a/layout/generic/nsContainerFrame.h
+++ b/layout/generic/nsContainerFrame.h
@@ -72,9 +72,6 @@ public:
                    PRUint32             aFlags = 0);
   virtual nsIFrame* GetFrameForPoint(const nsPoint&    aPoint, 
                                      nsFramePaintLayer aWhichLayer);
-  NS_IMETHOD ReplaceFrame(nsIAtom*        aListName,
-                          nsIFrame*       aOldFrame,
-                          nsIFrame*       aNewFrame);
   NS_IMETHOD ReflowDirtyChild(nsIPresShell* aPresShell, nsIFrame* aChild);
 
   virtual PRBool IsLeaf() const;
diff --git a/layout/generic/nsFrame.cpp b/layout/generic/nsFrame.cpp
index 601a3d935576..fd58b67eecc6 100644
--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -617,15 +617,6 @@ nsFrame::RemoveFrame(nsIAtom*        aListName,
   return NS_ERROR_UNEXPECTED;
 }
 
-NS_IMETHODIMP
-nsFrame::ReplaceFrame(nsIAtom*        aListName,
-                      nsIFrame*       aOldFrame,
-                      nsIFrame*       aNewFrame)
-{
-  NS_PRECONDITION(PR_FALSE, "not a container");
-  return NS_ERROR_UNEXPECTED;
-}
-
 NS_IMETHODIMP
 nsFrame::Destroy(nsPresContext* aPresContext)
 {
diff --git a/layout/generic/nsFrame.h b/layout/generic/nsFrame.h
index b75842fbfd62..bb965a63c453 100644
--- a/layout/generic/nsFrame.h
+++ b/layout/generic/nsFrame.h
@@ -176,9 +176,6 @@ public:
                            nsIFrame*       aFrameList);
   NS_IMETHOD  RemoveFrame(nsIAtom*        aListName,
                           nsIFrame*       aOldFrame);
-  NS_IMETHOD  ReplaceFrame(nsIAtom*        aListName,
-                           nsIFrame*       aOldFrame,
-                           nsIFrame*       aNewFrame);
   NS_IMETHOD  Destroy(nsPresContext* aPresContext);
   NS_IMETHOD  CalcBorderPadding(nsMargin& aBorderPadding) const;
   virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const;
diff --git a/layout/generic/nsFrameList.cpp b/layout/generic/nsFrameList.cpp
index cc7f1134b810..257cbb908479 100644
--- a/layout/generic/nsFrameList.cpp
+++ b/layout/generic/nsFrameList.cpp
@@ -299,58 +299,6 @@ nsFrameList::InsertFrames(nsIFrame* aParent,
 #endif
 }
 
-PRBool
-nsFrameList::DoReplaceFrame(nsIFrame* aParent,
-                            nsIFrame* aOldFrame,
-                            nsIFrame* aNewFrame)
-{
-  NS_PRECONDITION(aOldFrame, "null ptr");
-  NS_PRECONDITION(aNewFrame, "null ptr");
-  if (!aOldFrame || !aNewFrame) {
-    return PR_FALSE;
-  }
-  
-  nsIFrame* nextFrame = aOldFrame->GetNextSibling();
-  if (aOldFrame == mFirstChild) {
-    mFirstChild = aNewFrame;
-  }
-  else {
-    nsIFrame* prevSibling = GetPrevSiblingFor(aOldFrame);
-    if (!prevSibling) {
-      NS_WARNING("nsFrameList::ReplaceFrame: aOldFrame not found in list");
-      return PR_FALSE;
-    }
-    prevSibling->SetNextSibling(aNewFrame);
-  }
-
-  aNewFrame->SetNextSibling(nextFrame);
-  
-  if (aParent) {
-    aNewFrame->SetParent(aParent);
-  }
-#ifdef DEBUG
-  CheckForLoops();
-#endif
-  return PR_TRUE;
-}
-
-PRBool
-nsFrameList::ReplaceFrame(nsIFrame* aParent,
-                          nsIFrame* aOldFrame,
-                          nsIFrame* aNewFrame,
-                          PRBool aDestroy)
-{
-  NS_PRECONDITION(aOldFrame, "null ptr");
-  NS_PRECONDITION(aNewFrame, "null ptr");
-  if (DoReplaceFrame(aParent, aOldFrame, aNewFrame)) {
-    if (aDestroy) {
-      aOldFrame->Destroy(aOldFrame->GetPresContext());
-    }
-    return PR_TRUE;
-  }
-  return PR_FALSE;
-}
-
 PRBool
 nsFrameList::Split(nsIFrame* aAfterFrame, nsIFrame** aNextFrameResult)
 {
diff --git a/layout/generic/nsFrameList.h b/layout/generic/nsFrameList.h
index 23d32094d723..79f1c333819c 100644
--- a/layout/generic/nsFrameList.h
+++ b/layout/generic/nsFrameList.h
@@ -108,11 +108,6 @@ public:
     aFrameList.mFirstChild = nsnull;
   }
 
-  PRBool ReplaceFrame(nsIFrame* aParent,
-                      nsIFrame* aOldFrame,
-                      nsIFrame* aNewFrame,
-                      PRBool aDestroy);
-
   PRBool Split(nsIFrame* aAfterFrame, nsIFrame** aNextFrameResult);
 
   /**
@@ -168,10 +163,6 @@ public:
 #endif
 
 private:
-  PRBool DoReplaceFrame(nsIFrame* aParent,
-                        nsIFrame* aOldFrame,
-                        nsIFrame* aNewFrame);
-
 #ifdef DEBUG
   void CheckForLoops();
 #endif
diff --git a/layout/generic/nsGfxScrollFrame.cpp b/layout/generic/nsGfxScrollFrame.cpp
index b4adc7fc27d6..e80e0c328acf 100644
--- a/layout/generic/nsGfxScrollFrame.cpp
+++ b/layout/generic/nsGfxScrollFrame.cpp
@@ -215,17 +215,6 @@ nsHTMLScrollFrame::RemoveFrame(nsIAtom*  aListName,
 }
 
 
-NS_IMETHODIMP
-nsHTMLScrollFrame::ReplaceFrame(nsIAtom*  aListName,
-                                nsIFrame* aOldFrame,
-                                nsIFrame* aNewFrame)
-{
-  NS_ASSERTION(!aListName, "Only main list supported");
-  nsresult rv = nsHTMLContainerFrame::ReplaceFrame(aListName, aOldFrame, aNewFrame);
-  mInner.ReloadChildFrames();
-  return rv;
-}
-
 PRIntn
 nsHTMLScrollFrame::GetSkipSides() const
 {
@@ -1095,16 +1084,6 @@ nsXULScrollFrame::RemoveFrame(nsIAtom*        aListName,
 }
 
 
-NS_IMETHODIMP
-nsXULScrollFrame::ReplaceFrame(nsIAtom*        aListName,
-                               nsIFrame*       aOldFrame,
-                               nsIFrame*       aNewFrame)
-{
-  nsresult rv = nsBoxFrame::ReplaceFrame(aListName, aOldFrame, aNewFrame);
-  mInner.ReloadChildFrames();
-  return rv;
-}
-
 NS_IMETHODIMP
 nsXULScrollFrame::GetPadding(nsMargin& aMargin)
 {
diff --git a/layout/generic/nsGfxScrollFrame.h b/layout/generic/nsGfxScrollFrame.h
index 8e447c6284ce..1018cfeb3aec 100644
--- a/layout/generic/nsGfxScrollFrame.h
+++ b/layout/generic/nsGfxScrollFrame.h
@@ -219,10 +219,6 @@ public:
                           nsIFrame*       aPrevFrame,
                           nsIFrame*       aFrameList);
 
-  NS_IMETHOD ReplaceFrame(nsIAtom*        aListName,
-                          nsIFrame*       aOldFrame,
-                          nsIFrame*       aNewFrame);
-
   NS_IMETHOD Destroy(nsPresContext* aPresContext);
 
   NS_IMETHOD RemoveFrame(nsIAtom*        aListName,
@@ -353,10 +349,6 @@ public:
                           nsIFrame*       aPrevFrame,
                           nsIFrame*       aFrameList);
 
-  NS_IMETHOD ReplaceFrame(nsIAtom*        aListName,
-                          nsIFrame*       aOldFrame,
-                          nsIFrame*       aNewFrame);
-
   NS_IMETHOD Destroy(nsPresContext* aPresContext);
 
   NS_IMETHOD RemoveFrame(nsIAtom*        aListName,
diff --git a/layout/generic/nsIFrame.h b/layout/generic/nsIFrame.h
index 8c11b4d09670..d137e45132d0 100644
--- a/layout/generic/nsIFrame.h
+++ b/layout/generic/nsIFrame.h
@@ -519,27 +519,6 @@ public:
   NS_IMETHOD RemoveFrame(nsIAtom*        aListName,
                          nsIFrame*       aOldFrame) = 0;
 
-  /**
-   * This method is responsible for replacing the old frame with the
-   * new frame. The old frame should be destroyed and the new frame inserted
-   * in its place in the specified child list.
-   *
-   * @param   aListName the name of the child list. A NULL pointer for the atom
-   *            name means the unnamed principal child list
-   * @param   aOldFrame the frame to remove
-   * @param   aNewFrame the frame to replace it with. The new frame has its
-   *            NS_FRAME_IS_DIRTY bit set
-   * @return  NS_ERROR_INVALID_ARG if there is no child list with the specified
-   *            name,
-   *          NS_ERROR_FAILURE if the old child frame is not in the specified
-   *            child list,
-   *          NS_ERROR_UNEXPECTED if the frame is an atomic frame,
-   *          NS_OK otherwise
-   */
-  NS_IMETHOD ReplaceFrame(nsIAtom*        aListName,
-                          nsIFrame*       aOldFrame,
-                          nsIFrame*       aNewFrame) = 0;
-
   /**
    * Get the content object associated with this frame. Does not add a reference.
    */
diff --git a/layout/generic/nsInlineFrame.cpp b/layout/generic/nsInlineFrame.cpp
index 30629377c2ef..3682f0c21c58 100644
--- a/layout/generic/nsInlineFrame.cpp
+++ b/layout/generic/nsInlineFrame.cpp
@@ -263,30 +263,6 @@ nsInlineFrame::RemoveFrame(nsIAtom*        aListName,
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsInlineFrame::ReplaceFrame(nsIAtom*        aListName,
-                            nsIFrame*       aOldFrame,
-                            nsIFrame*       aNewFrame)
-{
-  if (aListName) {
-    NS_ERROR("Don't have any special lists on inline frames!");
-    return NS_ERROR_INVALID_ARG;
-  }
-  if (!aOldFrame || !aNewFrame) {
-    NS_ERROR("Missing aOldFrame or aNewFrame");
-    return NS_ERROR_INVALID_ARG;
-  }
-
-  PRBool retval =
-    mFrames.ReplaceFrame(this, aOldFrame, aNewFrame, PR_TRUE);
-  
-  // Ask the parent frame to reflow me.
-  ReflowDirtyChild(GetPresContext()->PresShell(), nsnull);
-
-  return retval ? NS_OK : NS_ERROR_FAILURE;
-}
-
-
 NS_IMETHODIMP
 nsInlineFrame::Paint(nsPresContext*      aPresContext,
                      nsIRenderingContext& aRenderingContext,
@@ -1115,19 +1091,6 @@ nsPositionedInlineFrame::RemoveFrame(nsIAtom*        aListName,
   return rv;
 }
 
-NS_IMETHODIMP
-nsPositionedInlineFrame::ReplaceFrame(nsIAtom*        aListName,
-                                      nsIFrame*       aOldFrame,
-                                      nsIFrame*       aNewFrame)
-{
-  if (mAbsoluteContainer.GetChildListName() == aListName) {
-    return mAbsoluteContainer.ReplaceFrame(this, aListName, aOldFrame,
-                                           aNewFrame);
-  } else {
-    return nsInlineFrame::ReplaceFrame(aListName, aOldFrame, aNewFrame);
-  }
-}
-
 nsIAtom*
 nsPositionedInlineFrame::GetAdditionalChildListName(PRInt32 aIndex) const
 {
diff --git a/layout/generic/nsInlineFrame.h b/layout/generic/nsInlineFrame.h
index 09059d99d530..6c3f04e21961 100644
--- a/layout/generic/nsInlineFrame.h
+++ b/layout/generic/nsInlineFrame.h
@@ -81,9 +81,6 @@ public:
                           nsIFrame*       aFrameList);
   NS_IMETHOD RemoveFrame(nsIAtom*        aListName,
                          nsIFrame*       aOldFrame);
-  NS_IMETHOD ReplaceFrame(nsIAtom*        aListName,
-                          nsIFrame*       aOldFrame,
-                          nsIFrame*       aNewFrame);
   NS_IMETHOD Paint(nsPresContext*      aPresContext,
                    nsIRenderingContext& aRenderingContext,
                    const nsRect&        aDirtyRect,
@@ -214,9 +211,6 @@ public:
                           nsIFrame*       aFrameList);
   NS_IMETHOD RemoveFrame(nsIAtom*        aListName,
                          nsIFrame*       aOldFrame);
-  NS_IMETHOD ReplaceFrame(nsIAtom*        aListName,
-                          nsIFrame*       aOldFrame,
-                          nsIFrame*       aNewFrame);
 
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;
 
diff --git a/layout/mathml/base/src/nsMathMLContainerFrame.cpp b/layout/mathml/base/src/nsMathMLContainerFrame.cpp
index 0b146a61defc..162395135b1d 100644
--- a/layout/mathml/base/src/nsMathMLContainerFrame.cpp
+++ b/layout/mathml/base/src/nsMathMLContainerFrame.cpp
@@ -936,20 +936,6 @@ nsMathMLContainerFrame::RemoveFrame(nsIAtom*        aListName,
   return ChildListChanged(nsIDOMMutationEvent::REMOVAL);
 }
 
-NS_IMETHODIMP
-nsMathMLContainerFrame::ReplaceFrame(nsIAtom*        aListName,
-                                     nsIFrame*       aOldFrame,
-                                     nsIFrame*       aNewFrame)
-{
-  if (aListName || !aOldFrame || !aNewFrame) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  // Replace the old frame with the new frame in the list
-  mFrames.ReplaceFrame(this, aOldFrame, aNewFrame, PR_TRUE);
-
-  return ChildListChanged(nsIDOMMutationEvent::MODIFICATION);
-}
-
 NS_IMETHODIMP
 nsMathMLContainerFrame::AttributeChanged(PRInt32         aNameSpaceID,
                                          nsIAtom*        aAttribute,
diff --git a/layout/mathml/base/src/nsMathMLContainerFrame.h b/layout/mathml/base/src/nsMathMLContainerFrame.h
index 347e4f659489..bbc2f3950a06 100644
--- a/layout/mathml/base/src/nsMathMLContainerFrame.h
+++ b/layout/mathml/base/src/nsMathMLContainerFrame.h
@@ -142,11 +142,6 @@ public:
   RemoveFrame(nsIAtom*        aListName,
               nsIFrame*       aOldFrame);
 
-  NS_IMETHOD
-  ReplaceFrame(nsIAtom*        aListName,
-               nsIFrame*       aOldFrame,
-               nsIFrame*       aNewFrame);
-
   NS_IMETHODIMP
   ReflowDirtyChild(nsIPresShell* aPresShell, 
                    nsIFrame*     aChild);
@@ -377,17 +372,6 @@ public:
     return rv;
   }
 
-  NS_IMETHOD
-  ReplaceFrame(nsIAtom*        aListName,
-               nsIFrame*       aOldFrame,
-               nsIFrame*       aNewFrame)
-  {
-    NS_ASSERTION(!aListName, "internal error");
-    nsresult rv = nsBlockFrame::ReplaceFrame(aListName, aOldFrame, aNewFrame);
-    nsMathMLContainerFrame::ReLayoutChildren(this);
-    return rv;
-  }
-
   NS_IMETHOD
   RemoveFrame(nsIAtom*        aListName,
               nsIFrame*       aOldFrame)
@@ -464,17 +448,6 @@ public:
     return rv;
   }
 
-  NS_IMETHOD
-  ReplaceFrame(nsIAtom*        aListName,
-               nsIFrame*       aOldFrame,
-               nsIFrame*       aNewFrame)
-  {
-    NS_ASSERTION(!aListName, "internal error");
-    nsresult rv = nsInlineFrame::ReplaceFrame(aListName, aOldFrame, aNewFrame);
-    nsMathMLContainerFrame::ReLayoutChildren(this);
-    return rv;
-  }
-
   NS_IMETHOD
   RemoveFrame(nsIAtom*        aListName,
               nsIFrame*       aOldFrame)
diff --git a/layout/mathml/base/src/nsMathMLForeignFrameWrapper.h b/layout/mathml/base/src/nsMathMLForeignFrameWrapper.h
index e72d51a3d4b5..f9b8f50b09b8 100644
--- a/layout/mathml/base/src/nsMathMLForeignFrameWrapper.h
+++ b/layout/mathml/base/src/nsMathMLForeignFrameWrapper.h
@@ -122,22 +122,6 @@ public:
     return NS_ERROR_NOT_IMPLEMENTED;
   }
 
-  // need special care here because the base class implementation treats this
-  // as two operations: remove & insert; In our case, removing the child will
-  // remove us too... so we have to operate from our parent's perspective
-  NS_IMETHOD
-  ReplaceFrame(nsIAtom*        aListName,
-               nsIFrame*       aOldFrame,
-               nsIFrame*       aNewFrame)
-  {
-    nsresult rv = mParent->ReplaceFrame(aListName, this, aNewFrame);
-    // XXX the usage of ReplaceFrame() vs. ReplaceFrameAndDestroy() is
-    // XXX ambiguous - see bug 122748. The style system doesn't call ReplaceFrame()
-    // XXX and that's why nobody seems to have been biten by the ambiguity yet
-    aOldFrame->Destroy(GetPresContext());
-    return rv;
-  }
-
   // Our life is bound to the life of our unique child.
   // When our child goes away, we ask our parent to delete us
   NS_IMETHOD
diff --git a/layout/svg/base/src/nsSVGDefsFrame.cpp b/layout/svg/base/src/nsSVGDefsFrame.cpp
index e3155d484ebc..aa7913b9af70 100644
--- a/layout/svg/base/src/nsSVGDefsFrame.cpp
+++ b/layout/svg/base/src/nsSVGDefsFrame.cpp
@@ -182,15 +182,6 @@ nsSVGDefsFrame::RemoveFrame(nsIAtom*  aListName,
   return result ? NS_OK : NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP
-nsSVGDefsFrame::ReplaceFrame(nsIAtom*  aListName,
-                             nsIFrame* aOldFrame,
-                             nsIFrame* aNewFrame)
-{
-  NS_NOTYETIMPLEMENTED("nsSVGDefsFrame::ReplaceFrame");
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 nsIAtom *
 nsSVGDefsFrame::GetType() const
 {
diff --git a/layout/svg/base/src/nsSVGDefsFrame.h b/layout/svg/base/src/nsSVGDefsFrame.h
index cb9b7693c434..16d7be024d56 100644
--- a/layout/svg/base/src/nsSVGDefsFrame.h
+++ b/layout/svg/base/src/nsSVGDefsFrame.h
@@ -76,9 +76,6 @@ public:
                            nsIFrame*       aFrameList);
   NS_IMETHOD  RemoveFrame(nsIAtom*        aListName,
                           nsIFrame*       aOldFrame);
-  NS_IMETHOD  ReplaceFrame(nsIAtom*        aListName,
-                           nsIFrame*       aOldFrame,
-                           nsIFrame*       aNewFrame);
   NS_IMETHOD Init(nsPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
diff --git a/layout/svg/base/src/nsSVGForeignObjectFrame.cpp b/layout/svg/base/src/nsSVGForeignObjectFrame.cpp
index f1543f1245b9..1b50c5a44dae 100644
--- a/layout/svg/base/src/nsSVGForeignObjectFrame.cpp
+++ b/layout/svg/base/src/nsSVGForeignObjectFrame.cpp
@@ -107,10 +107,6 @@ public:
   NS_IMETHOD  RemoveFrame(nsIAtom*        aListName,
                           nsIFrame*       aOldFrame);
   
-  NS_IMETHOD  ReplaceFrame(nsIAtom*        aListName,
-                           nsIFrame*       aOldFrame,
-                           nsIFrame*       aNewFrame);
-
   /**
    * Get the "type" of the frame
    *
@@ -414,21 +410,6 @@ nsSVGForeignObjectFrame::RemoveFrame(nsIAtom*        aListName,
 	return rv;
 }
 
-NS_IMETHODIMP
-nsSVGForeignObjectFrame::ReplaceFrame(nsIAtom*        aListName,
-                                      nsIFrame*       aOldFrame,
-                                      nsIFrame*       aNewFrame)
-{
-#ifdef DEBUG
-  printf("**nsSVGForeignObjectFrame::ReplaceFrame()\n");
-#endif
-	nsresult rv;
-	rv = nsSVGForeignObjectFrameBase::ReplaceFrame(aListName, aOldFrame,
-                                                   aNewFrame);
-	Update();
-	return rv;
-}
-
 // XXX Need to make sure that any of the code examining
 // frametypes, particularly code looking at block and area
 // also handles foreignObject before we return our own frametype
diff --git a/layout/svg/base/src/nsSVGGenericContainerFrame.cpp b/layout/svg/base/src/nsSVGGenericContainerFrame.cpp
index 10d75335e975..53ca1e3cd4e0 100644
--- a/layout/svg/base/src/nsSVGGenericContainerFrame.cpp
+++ b/layout/svg/base/src/nsSVGGenericContainerFrame.cpp
@@ -155,15 +155,6 @@ nsSVGGenericContainerFrame::RemoveFrame(nsIAtom*        aListName,
   return result ? NS_OK : NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP
-nsSVGGenericContainerFrame::ReplaceFrame(nsIAtom*        aListName,
-                                         nsIFrame*       aOldFrame,
-                                         nsIFrame*       aNewFrame)
-{
-  NS_NOTYETIMPLEMENTED("nsSVGGenericContainerFrame::ReplaceFrame");
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 NS_IMETHODIMP
 nsSVGGenericContainerFrame::AttributeChanged(PRInt32         aNameSpaceID,
                                              nsIAtom*        aAttribute,
diff --git a/layout/svg/base/src/nsSVGGenericContainerFrame.h b/layout/svg/base/src/nsSVGGenericContainerFrame.h
index 1c639f7c3484..d2b41a4d8ede 100644
--- a/layout/svg/base/src/nsSVGGenericContainerFrame.h
+++ b/layout/svg/base/src/nsSVGGenericContainerFrame.h
@@ -76,9 +76,6 @@ public:
                            nsIFrame*       aFrameList);
   NS_IMETHOD  RemoveFrame(nsIAtom*        aListName,
                           nsIFrame*       aOldFrame);
-  NS_IMETHOD  ReplaceFrame(nsIAtom*        aListName,
-                           nsIFrame*       aOldFrame,
-                           nsIFrame*       aNewFrame);
   NS_IMETHOD Init(nsPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
diff --git a/layout/svg/base/src/nsSVGInnerSVGFrame.cpp b/layout/svg/base/src/nsSVGInnerSVGFrame.cpp
index 93525c43c1c0..09e22e7581aa 100644
--- a/layout/svg/base/src/nsSVGInnerSVGFrame.cpp
+++ b/layout/svg/base/src/nsSVGInnerSVGFrame.cpp
@@ -89,9 +89,6 @@ public:
                            nsIFrame*      aFrameList);
   NS_IMETHOD  RemoveFrame(nsIAtom*       aListName,
                           nsIFrame*      aOldFrame);
-  NS_IMETHOD  ReplaceFrame(nsIAtom*       aListName,
-                           nsIFrame*      aOldFrame,
-                           nsIFrame*      aNewFrame);
   NS_IMETHOD Init(nsPresContext*  aPresContext,
                   nsIContent*     aContent,
                   nsIFrame*       aParent,
@@ -329,15 +326,6 @@ nsSVGInnerSVGFrame::RemoveFrame(nsIAtom*       aListName,
   return result ? NS_OK : NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP
-nsSVGInnerSVGFrame::ReplaceFrame(nsIAtom*       aListName,
-                                 nsIFrame*      aOldFrame,
-                                 nsIFrame*      aNewFrame)
-{
-  NS_NOTYETIMPLEMENTED("nsSVGInnerSVGFrame::ReplaceFrame");
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 NS_IMETHODIMP
 nsSVGInnerSVGFrame::AttributeChanged(PRInt32        aNameSpaceID,
                                      nsIAtom*       aAttribute,
diff --git a/layout/svg/base/src/nsSVGOuterSVGFrame.cpp b/layout/svg/base/src/nsSVGOuterSVGFrame.cpp
index 821e586493c9..a4cc9d442324 100644
--- a/layout/svg/base/src/nsSVGOuterSVGFrame.cpp
+++ b/layout/svg/base/src/nsSVGOuterSVGFrame.cpp
@@ -195,9 +195,6 @@ public:
                            nsIFrame*       aFrameList);
   NS_IMETHOD  RemoveFrame(nsIAtom*        aListName,
                           nsIFrame*       aOldFrame);
-  NS_IMETHOD  ReplaceFrame(nsIAtom*        aListName,
-                           nsIFrame*       aOldFrame,
-                           nsIFrame*       aNewFrame);
 
   NS_IMETHOD  AttributeChanged(PRInt32         aNameSpaceID,
                                nsIAtom*        aAttribute,
@@ -665,15 +662,6 @@ nsSVGOuterSVGFrame::RemoveFrame(nsIAtom*        aListName,
   return result ? NS_OK : NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP
-nsSVGOuterSVGFrame::ReplaceFrame(nsIAtom*        aListName,
-                                 nsIFrame*       aOldFrame,
-                                 nsIFrame*       aNewFrame)
-{
-  NS_NOTYETIMPLEMENTED("nsSVGOuterSVGFrame::ReplaceFrame");
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 NS_IMETHODIMP
 nsSVGOuterSVGFrame::AttributeChanged(PRInt32         aNameSpaceID,
                                      nsIAtom*        aAttribute,
diff --git a/layout/svg/base/src/nsSVGTSpanFrame.cpp b/layout/svg/base/src/nsSVGTSpanFrame.cpp
index 07f8df058d2d..93758e096a50 100644
--- a/layout/svg/base/src/nsSVGTSpanFrame.cpp
+++ b/layout/svg/base/src/nsSVGTSpanFrame.cpp
@@ -266,15 +266,6 @@ nsSVGTSpanFrame::RemoveFrame(nsIAtom*        aListName,
   return result ? NS_OK : NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP
-nsSVGTSpanFrame::ReplaceFrame(nsIAtom*        aListName,
-                              nsIFrame*       aOldFrame,
-                              nsIFrame*       aNewFrame)
-{
-  NS_NOTYETIMPLEMENTED("nsSVGTSpanFrame::ReplaceFrame");
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 //----------------------------------------------------------------------
 // nsISVGValueObserver methods:
 
diff --git a/layout/svg/base/src/nsSVGTSpanFrame.h b/layout/svg/base/src/nsSVGTSpanFrame.h
index 2110283a9f48..2582a7992af0 100644
--- a/layout/svg/base/src/nsSVGTSpanFrame.h
+++ b/layout/svg/base/src/nsSVGTSpanFrame.h
@@ -100,9 +100,6 @@ public:
                            nsIFrame*       aFrameList);
   NS_IMETHOD  RemoveFrame(nsIAtom*        aListName,
                           nsIFrame*       aOldFrame);
-  NS_IMETHOD  ReplaceFrame(nsIAtom*        aListName,
-                           nsIFrame*       aOldFrame,
-                           nsIFrame*       aNewFrame);
   NS_IMETHOD Init(nsPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
diff --git a/layout/svg/base/src/nsSVGTextFrame.cpp b/layout/svg/base/src/nsSVGTextFrame.cpp
index 05062708e9de..254ca9a1da06 100644
--- a/layout/svg/base/src/nsSVGTextFrame.cpp
+++ b/layout/svg/base/src/nsSVGTextFrame.cpp
@@ -102,9 +102,6 @@ public:
                            nsIFrame*       aFrameList);
   NS_IMETHOD  RemoveFrame(nsIAtom*        aListName,
                           nsIFrame*       aOldFrame);
-  NS_IMETHOD  ReplaceFrame(nsIAtom*        aListName,
-                           nsIFrame*       aOldFrame,
-                           nsIFrame*       aNewFrame);
   
   NS_IMETHOD Init(nsPresContext*  aPresContext,
                   nsIContent*      aContent,
@@ -443,15 +440,6 @@ nsSVGTextFrame::RemoveFrame(nsIAtom*        aListName,
   return result ? NS_OK : NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP
-nsSVGTextFrame::ReplaceFrame(nsIAtom*        aListName,
-                             nsIFrame*       aOldFrame,
-                             nsIFrame*       aNewFrame)
-{
-  NS_NOTYETIMPLEMENTED("nsSVGTextFrame::ReplaceFrame");
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 //----------------------------------------------------------------------
 // nsISVGValueObserver methods: