diff --git a/dom/base/nsDOMWindowUtils.cpp b/dom/base/nsDOMWindowUtils.cpp
index 08f94bb33950..05e34c69f6e8 100644
--- a/dom/base/nsDOMWindowUtils.cpp
+++ b/dom/base/nsDOMWindowUtils.cpp
@@ -2317,26 +2317,3 @@ nsDOMWindowUtils::GetPlugins(JSContext* cx, jsval* aPlugins)
   *aPlugins = OBJECT_TO_JSVAL(jsPlugins);
   return NS_OK;
 }
-
-NS_IMETHODIMP
-nsDOMWindowUtils::SetScrollPositionClampingScrollPortSize(float aWidth, float aHeight)
-{
-  if (!IsUniversalXPConnectCapable()) {
-    return NS_ERROR_DOM_SECURITY_ERR;
-  }
-
-  if (!(aWidth >= 0.0 && aHeight >= 0.0)) {
-    return NS_ERROR_ILLEGAL_VALUE;
-  }
-
-  nsIPresShell* presShell = GetPresShell();
-  if (!presShell) {
-    return NS_ERROR_FAILURE;
-  }
-
-  presShell->SetScrollPositionClampingScrollPortSize(
-    nsPresContext::CSSPixelsToAppUnits(aWidth),
-    nsPresContext::CSSPixelsToAppUnits(aHeight));
-
-  return NS_OK;
-}
diff --git a/dom/interfaces/base/nsIDOMWindowUtils.idl b/dom/interfaces/base/nsIDOMWindowUtils.idl
index f88eee4e447b..a86f14081ae0 100644
--- a/dom/interfaces/base/nsIDOMWindowUtils.idl
+++ b/dom/interfaces/base/nsIDOMWindowUtils.idl
@@ -70,7 +70,7 @@ interface nsIDOMFile;
 interface nsIFile;
 interface nsIDOMTouch;
 
-[scriptable, uuid(66a68858-df38-40e1-a792-fda04ebcc084)]
+[scriptable, uuid(c7f303a1-4f7b-4d38-a192-c3f0e25dadb1)]
 interface nsIDOMWindowUtils : nsISupports {
 
   /**
@@ -1110,12 +1110,4 @@ interface nsIDOMWindowUtils : nsISupports {
    */
   [implicit_jscontext]
   readonly attribute jsval plugins;
-
-  /**
-   * Set the scrollport size for the purposes of clamping scroll positions for
-   * the root scroll frame of this document to be (aWidth,aHeight) in CSS pixels.
-   *
-   * The caller of this method must have UniversalXPConnect privileges.
-   */
-  void setScrollPositionClampingScrollPortSize(in float aWidth, in float aHeight);
 };
diff --git a/layout/base/nsIPresShell.h b/layout/base/nsIPresShell.h
index 512e77d974e1..2e4b4119cbf3 100644
--- a/layout/base/nsIPresShell.h
+++ b/layout/base/nsIPresShell.h
@@ -1265,15 +1265,6 @@ public:
   // clears that capture.
   static void ClearMouseCapture(nsIFrame* aFrame);
 
-  void SetScrollPositionClampingScrollPortSize(nscoord aWidth, nscoord aHeight);
-  bool IsScrollPositionClampingScrollPortSizeSet() {
-    return mScrollPositionClampingScrollPortSizeSet;
-  }
-  nsSize GetScrollPositionClampingScrollPortSize() {
-    NS_ASSERTION(mScrollPositionClampingScrollPortSizeSet, "asking for scroll port when its not set?");
-    return mScrollPositionClampingScrollPortSize;
-  }
-
 protected:
   friend class nsRefreshDriver;
 
@@ -1324,8 +1315,6 @@ protected:
 
   bool                      mSuppressInterruptibleReflows;
 
-  bool                      mScrollPositionClampingScrollPortSizeSet;
-
   // A list of weak frames. This is a pointer to the last item in the list.
   nsWeakFrame*              mWeakFrames;
 
@@ -1344,8 +1333,6 @@ protected:
   float                     mXResolution;
   float                     mYResolution;
 
-  nsSize                    mScrollPositionClampingScrollPortSize;
-
   static nsIContent* gKeyDownTarget;
 };
 
diff --git a/layout/base/nsPresShell.cpp b/layout/base/nsPresShell.cpp
index 5f8c6a159abf..edd4e6bd7b3a 100644
--- a/layout/base/nsPresShell.cpp
+++ b/layout/base/nsPresShell.cpp
@@ -831,8 +831,6 @@ PresShell::PresShell()
   mYResolution = 1.0;
   mViewportOverridden = false;
 
-  mScrollPositionClampingScrollPortSizeSet = false;
-
   static bool addedSynthMouseMove = false;
   if (!addedSynthMouseMove) {
     Preferences::AddBoolVarCache(&sSynthMouseMove,
@@ -9149,10 +9147,3 @@ PresShell::SizeOfTextRuns(nsMallocSizeOfFun aMallocSizeOf) const
                                                 /* clear = */false);
 }
 
-void
-nsIPresShell::SetScrollPositionClampingScrollPortSize(nscoord aWidth, nscoord aHeight)
-{
-  mScrollPositionClampingScrollPortSizeSet = true;
-  mScrollPositionClampingScrollPortSize.width = aWidth;
-  mScrollPositionClampingScrollPortSize.height = aHeight;
-}
diff --git a/layout/generic/nsGfxScrollFrame.cpp b/layout/generic/nsGfxScrollFrame.cpp
index 980a6a8b7681..7c8de465176c 100644
--- a/layout/generic/nsGfxScrollFrame.cpp
+++ b/layout/generic/nsGfxScrollFrame.cpp
@@ -1645,7 +1645,7 @@ Clamp(nscoord aLower, nscoord aVal, nscoord aUpper)
 nsPoint
 nsGfxScrollFrameInner::ClampScrollPosition(const nsPoint& aPt) const
 {
-  nsRect range = GetScrollRangeForClamping();
+  nsRect range = GetScrollRange();
   return nsPoint(Clamp(range.x, aPt.x, range.XMost()),
                  Clamp(range.y, aPt.y, range.YMost()));
 }
@@ -1971,7 +1971,7 @@ nsGfxScrollFrameInner::RestrictToDevPixels(const nsPoint& aPt,
   // pixels. But we also need to make sure that our position remains
   // inside the allowed region.
   if (aShouldClamp) {
-    nsRect scrollRange = GetScrollRangeForClamping();
+    nsRect scrollRange = GetScrollRange();
     *aPtDevPx = nsIntPoint(ClampInt(scrollRange.x, aPt.x, scrollRange.XMost(), appUnitsPerDevPixel),
                            ClampInt(scrollRange.y, aPt.y, scrollRange.YMost(), appUnitsPerDevPixel));
   } else {
@@ -2326,16 +2326,10 @@ AlignToDevPixelRoundingToZero(nscoord aVal, PRInt32 aAppUnitsPerDevPixel)
 
 nsRect
 nsGfxScrollFrameInner::GetScrollRange() const
-{
-  return GetScrollRange(mScrollPort.width, mScrollPort.height);
-}
-
-nsRect
-nsGfxScrollFrameInner::GetScrollRange(nscoord aWidth, nscoord aHeight) const
 {
   nsRect range = GetScrolledRect();
-  range.width -= aWidth;
-  range.height -= aHeight;
+  range.width -= mScrollPort.width;
+  range.height -= mScrollPort.height;
 
   nsPresContext* presContext = mOuter->PresContext();
   PRInt32 appUnitsPerDevPixel = presContext->AppUnitsPerDevPixel();
@@ -2348,17 +2342,6 @@ nsGfxScrollFrameInner::GetScrollRange(nscoord aWidth, nscoord aHeight) const
   return range;
 }
 
-nsRect
-nsGfxScrollFrameInner::GetScrollRangeForClamping() const
-{
-  nsIPresShell* presShell = mOuter->PresContext()->PresShell();
-  if (presShell->IsScrollPositionClampingScrollPortSizeSet()) {
-    nsSize size = presShell->GetScrollPositionClampingScrollPortSize();
-    return GetScrollRange(size.width, size.height);
-  }
-  return GetScrollRange();
-}
-
 static void
 AdjustForWholeDelta(PRInt32 aDelta, nscoord* aCoord)
 {
diff --git a/layout/generic/nsGfxScrollFrame.h b/layout/generic/nsGfxScrollFrame.h
index c0f679f6c957..28b73bca44a6 100644
--- a/layout/generic/nsGfxScrollFrame.h
+++ b/layout/generic/nsGfxScrollFrame.h
@@ -178,12 +178,7 @@ public:
     return pt;
   }
   nsRect GetScrollRange() const;
-  // Get the scroll range assuming the scrollport has size (aWidth, aHeight).
-  nsRect GetScrollRange(nscoord aWidth, nscoord aHeight) const;
-protected:
-  nsRect GetScrollRangeForClamping() const;
 
-public:
   nsPoint RestrictToDevPixels(const nsPoint& aPt, nsIntPoint* aPtDevPx, bool aShouldClamp) const;
   nsPoint ClampScrollPosition(const nsPoint& aPt) const;
   static void AsyncScrollCallback(nsITimer *aTimer, void* anInstance);