diff --git a/layout/base/nsLayoutUtils.cpp b/layout/base/nsLayoutUtils.cpp
index 3458f4ca19e..6fac67a6800 100644
--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -1260,9 +1260,6 @@ AddRectsForFrame(nsIFrame* aFrame, nsIFrame* aRelativeTo,
     nsRect r;
     nsIFrame* outer = nsSVGUtils::GetOuterSVGFrameAndCoveredRegion(aFrame, &r);
     if (outer) {
-      // r is in pixels relative to 'outer', get it into appunits
-      // relative to aRelativeTo
-      r.ScaleRoundOut(1.0/aFrame->PresContext()->AppUnitsPerDevPixel());
       aCallback->AddRect(r + outer->GetOffsetTo(aRelativeTo));
     } else
 #endif
diff --git a/layout/svg/base/src/nsISVGChildFrame.h b/layout/svg/base/src/nsISVGChildFrame.h
index f9b6b0e42fe..9dc3cc97ce4 100644
--- a/layout/svg/base/src/nsISVGChildFrame.h
+++ b/layout/svg/base/src/nsISVGChildFrame.h
@@ -42,17 +42,17 @@
 
 #include "nsISupports.h"
 #include "nsCOMPtr.h"
+#include "nsRect.h"
 
 class gfxContext;
 class nsPresContext;
 class nsIDOMSVGRect;
 class nsIDOMSVGMatrix;
 class nsSVGRenderState;
-struct nsRect;
 
 #define NS_ISVGCHILDFRAME_IID \
-{ 0x667e8781, 0x72bd, 0x4344, \
- { 0x95, 0x8c, 0x69, 0xa5, 0x70, 0xc4, 0xcc, 0xb3 } }
+{ 0xe4ecddbf, 0xde7c, 0x4cd9, \
+ { 0x92, 0x4a, 0xfa, 0x81, 0xba, 0x83, 0x26, 0x69 } }
 
 class nsISVGChildFrame : public nsISupports {
 public:
@@ -61,20 +61,15 @@ public:
 
   // Paint this frame - aDirtyRect is the area being redrawn, in frame
   // offset pixel coordinates
-  NS_IMETHOD PaintSVG(nsSVGRenderState* aContext, nsRect *aDirtyRect)=0;
+  NS_IMETHOD PaintSVG(nsSVGRenderState* aContext, nsIntRect *aDirtyRect)=0;
 
   // Check if this frame or children contain the given point,
-  // specified in device pixels relative to the origin of the outer
+  // specified in app units relative to the origin of the outer
   // svg frame (origin ill-defined in the case of borders - bug
-  // 290770).  Return value unspecified (usually NS_OK for hit, error
-  // no hit, but not always [ex: nsSVGPathGeometryFrame.cpp]) and no
-  // code trusts the return value - this should be fixed (bug 290765).
-  // *hit set to topmost frame in the children (or 'this' if leaf
-  // frame) which is accepting pointer events, null if no frame hit.
-  // See bug 290852 for foreignObject complications.
-  NS_IMETHOD GetFrameForPointSVG(float x, float y, nsIFrame** hit)=0;
+  // 290770).  See bug 290852 for foreignObject complications.
+  NS_IMETHOD_(nsIFrame*) GetFrameForPoint(const nsPoint &aPoint)=0;
 
-  // Get bounds in our gfxContext's coordinates space (in device pixels)
+  // Get bounds in our gfxContext's coordinates space (in app units)
   NS_IMETHOD_(nsRect) GetCoveredRegion()=0;
   NS_IMETHOD UpdateCoveredRegion()=0;
 
diff --git a/layout/svg/base/src/nsSVGClipPathFrame.cpp b/layout/svg/base/src/nsSVGClipPathFrame.cpp
index 61a8bc673fb..61c5c78a719 100644
--- a/layout/svg/base/src/nsSVGClipPathFrame.cpp
+++ b/layout/svg/base/src/nsSVGClipPathFrame.cpp
@@ -105,7 +105,7 @@ nsSVGClipPathFrame::ClipPaint(nsSVGRenderState* aContext,
 PRBool
 nsSVGClipPathFrame::ClipHitTest(nsISVGChildFrame* aParent,
                                 nsIDOMSVGMatrix *aMatrix,
-                                float aX, float aY)
+                                const nsPoint &aPoint)
 {
   // If the flag is set when we get here, it means this clipPath frame
   // has already been used in hit testing against the current clip,
@@ -116,7 +116,6 @@ nsSVGClipPathFrame::ClipHitTest(nsISVGChildFrame* aParent,
   }
   AutoClipPathReferencer clipRef(this);
 
-  nsRect dirty;
   mClipParent = aParent,
   mClipParentMatrix = aMatrix;
 
@@ -130,9 +129,7 @@ nsSVGClipPathFrame::ClipHitTest(nsISVGChildFrame* aParent,
       // (used to shortcut hit testing).
       SVGFrame->NotifySVGChanged(nsISVGChildFrame::TRANSFORM_CHANGED);
 
-      nsIFrame *temp = nsnull;
-      nsresult rv = SVGFrame->GetFrameForPointSVG(aX, aY, &temp);
-      if (NS_SUCCEEDED(rv) && temp)
+      if (SVGFrame->GetFrameForPoint(aPoint))
         return PR_TRUE;
     }
   }
diff --git a/layout/svg/base/src/nsSVGClipPathFrame.h b/layout/svg/base/src/nsSVGClipPathFrame.h
index 16365322209..d15ecbe3895 100644
--- a/layout/svg/base/src/nsSVGClipPathFrame.h
+++ b/layout/svg/base/src/nsSVGClipPathFrame.h
@@ -59,7 +59,7 @@ public:
 
   PRBool ClipHitTest(nsISVGChildFrame* aParent,
                      nsIDOMSVGMatrix *aMatrix,
-                     float aX, float aY);
+                     const nsPoint &aPoint);
 
   // Check if this clipPath is made up of more than one geometry object.
   // If so, the clipping API in cairo isn't enough and we need to use
diff --git a/layout/svg/base/src/nsSVGContainerFrame.cpp b/layout/svg/base/src/nsSVGContainerFrame.cpp
index 2ce6e80d02f..9f6f16a8bed 100644
--- a/layout/svg/base/src/nsSVGContainerFrame.cpp
+++ b/layout/svg/base/src/nsSVGContainerFrame.cpp
@@ -165,7 +165,7 @@ nsSVGDisplayContainerFrame::RemoveFrame(nsIAtom* aListName,
 
 NS_IMETHODIMP
 nsSVGDisplayContainerFrame::PaintSVG(nsSVGRenderState* aContext,
-                                     nsRect *aDirtyRect)
+                                     nsIntRect *aDirtyRect)
 {
   const nsStyleDisplay *display = mStyleContext->GetStyleDisplay();
   if (display->mOpacity == 0.0)
@@ -179,12 +179,10 @@ nsSVGDisplayContainerFrame::PaintSVG(nsSVGRenderState* aContext,
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsSVGDisplayContainerFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
+NS_IMETHODIMP_(nsIFrame*)
+nsSVGDisplayContainerFrame::GetFrameForPoint(const nsPoint &aPoint)
 {
-  nsSVGUtils::HitTestChildren(this, x, y, hit);
-  
-  return NS_OK;
+  return nsSVGUtils::HitTestChildren(this, aPoint);
 }
 
 NS_IMETHODIMP_(nsRect)
diff --git a/layout/svg/base/src/nsSVGContainerFrame.h b/layout/svg/base/src/nsSVGContainerFrame.h
index 41fb6323b00..b1c4f012745 100644
--- a/layout/svg/base/src/nsSVGContainerFrame.h
+++ b/layout/svg/base/src/nsSVGContainerFrame.h
@@ -101,8 +101,8 @@ public:
                   nsIFrame*        aPrevInFlow);
 
   // nsISVGChildFrame interface:
-  NS_IMETHOD PaintSVG(nsSVGRenderState* aContext, nsRect *aDirtyRect);
-  NS_IMETHOD GetFrameForPointSVG(float x, float y, nsIFrame** hit);  
+  NS_IMETHOD PaintSVG(nsSVGRenderState* aContext, nsIntRect *aDirtyRect);
+  NS_IMETHOD_(nsIFrame*) GetFrameForPoint(const nsPoint &aPoint);
   NS_IMETHOD_(nsRect) GetCoveredRegion();
   NS_IMETHOD UpdateCoveredRegion();
   NS_IMETHOD InitialUpdate();
diff --git a/layout/svg/base/src/nsSVGEffects.cpp b/layout/svg/base/src/nsSVGEffects.cpp
index edb387620aa..5ef7b67230b 100644
--- a/layout/svg/base/src/nsSVGEffects.cpp
+++ b/layout/svg/base/src/nsSVGEffects.cpp
@@ -138,9 +138,9 @@ nsSVGFilterProperty::DoUpdate()
 {
   nsSVGOuterSVGFrame *outerSVGFrame = nsSVGUtils::GetOuterSVGFrame(mFrame);
   if (outerSVGFrame) {
-    outerSVGFrame->InvalidateRect(mFilterRect);
+    outerSVGFrame->Invalidate(mFilterRect);
     UpdateRect();
-    outerSVGFrame->InvalidateRect(mFilterRect);
+    outerSVGFrame->Invalidate(mFilterRect);
   }
 }
 
diff --git a/layout/svg/base/src/nsSVGFilterFrame.cpp b/layout/svg/base/src/nsSVGFilterFrame.cpp
index f69096421e2..0a323355170 100644
--- a/layout/svg/base/src/nsSVGFilterFrame.cpp
+++ b/layout/svg/base/src/nsSVGFilterFrame.cpp
@@ -63,7 +63,7 @@ NS_NewSVGFilterFrame(nsIPresShell* aPresShell, nsIContent* aContent, nsStyleCont
 static nsIntRect
 MapDeviceRectToFilterSpace(const gfxMatrix& aMatrix,
                            const gfxIntSize& aFilterSize,
-                           const nsRect* aDeviceRect)
+                           const nsIntRect* aDeviceRect)
 {
   nsIntRect rect(0, 0, aFilterSize.width, aFilterSize.height);
   if (aDeviceRect) {
@@ -80,8 +80,8 @@ MapDeviceRectToFilterSpace(const gfxMatrix& aMatrix,
 
 nsresult
 nsSVGFilterFrame::CreateInstance(nsISVGChildFrame *aTarget,
-                                 const nsRect *aDirtyOutputRect,
-                                 const nsRect *aDirtyInputRect,
+                                 const nsIntRect *aDirtyOutputRect,
+                                 const nsIntRect *aDirtyInputRect,
                                  nsSVGFilterInstance **aInstance)
 {
   *aInstance = nsnull;
@@ -203,7 +203,7 @@ RestoreTargetState(nsISVGChildFrame *aTarget)
 nsresult
 nsSVGFilterFrame::FilterPaint(nsSVGRenderState *aContext,
                               nsISVGChildFrame *aTarget,
-                              const nsRect *aDirtyRect)
+                              const nsIntRect *aDirtyRect)
 {
   nsAutoPtr<nsSVGFilterInstance> instance;
   nsresult rv = CreateInstance(aTarget, aDirtyRect, nsnull, getter_Transfers(instance));
@@ -238,10 +238,13 @@ nsSVGFilterFrame::GetInvalidationRegion(nsIFrame *aTarget, const nsRect& aRect)
   nsISVGChildFrame *svg;
   CallQueryInterface(aTarget, &svg);
 
+  nscoord p2a = aTarget->PresContext()->AppUnitsPerDevPixel();
   nsRect result = aRect;
+  nsIntRect rect = aRect;
+  rect.ScaleRoundOut(1.0/p2a);
 
   nsAutoPtr<nsSVGFilterInstance> instance;
-  nsresult rv = CreateInstance(svg, nsnull, &aRect, getter_Transfers(instance));
+  nsresult rv = CreateInstance(svg, nsnull, &rect, getter_Transfers(instance));
   if (NS_SUCCEEDED(rv)) {
     if (!instance) {
       // The filter draws nothing, so nothing is dirty.
@@ -262,6 +265,7 @@ nsSVGFilterFrame::GetInvalidationRegion(nsIFrame *aTarget, const nsRect& aRect)
         nsIntRect deviceRect;
         rv = nsSVGUtils::GfxRectToIntRect(r, &deviceRect);
         if (NS_SUCCEEDED(rv)) {
+          deviceRect.ScaleRoundOut(p2a);
           result = deviceRect;
         }
       }
diff --git a/layout/svg/base/src/nsSVGFilterFrame.h b/layout/svg/base/src/nsSVGFilterFrame.h
index 8185baf8675..13fd9a593c4 100644
--- a/layout/svg/base/src/nsSVGFilterFrame.h
+++ b/layout/svg/base/src/nsSVGFilterFrame.h
@@ -53,13 +53,13 @@ protected:
 public:    
   nsresult FilterPaint(nsSVGRenderState *aContext,
                        nsISVGChildFrame *aTarget,
-                       const nsRect* aDirtyRect);
+                       const nsIntRect* aDirtyRect);
 
   // Returns invalidation region for filter (can be bigger than the
-  // referencing geometry to filter region sizing) in device pixels
+  // referencing geometry to filter region sizing) in app units
   // relative to the origin of the outer svg.
-  // aRect is the area of device pixels that would be invalidated. Normally
-  // you'd just pass aTarget->GetRect() here.
+  // aRect is the area that would be invalidated. Normally you'd just pass
+  // aTarget->GetRect() here.
   nsRect GetInvalidationRegion(nsIFrame *aTarget, const nsRect& aRect);
 
   /**
@@ -72,8 +72,8 @@ public:
 private:
   // implementation helpers
   nsresult CreateInstance(nsISVGChildFrame *aTarget,
-                          const nsRect *aDirtyOutputRect,
-                          const nsRect *aDirtyInputRect,
+                          const nsIntRect *aDirtyOutputRect,
+                          const nsIntRect *aDirtyInputRect,
                           nsSVGFilterInstance **aInstance);
 };
 
diff --git a/layout/svg/base/src/nsSVGForeignObjectFrame.cpp b/layout/svg/base/src/nsSVGForeignObjectFrame.cpp
index 94027b82074..c0df04e83fc 100644
--- a/layout/svg/base/src/nsSVGForeignObjectFrame.cpp
+++ b/layout/svg/base/src/nsSVGForeignObjectFrame.cpp
@@ -185,13 +185,13 @@ nsSVGForeignObjectFrame::InvalidateInternal(const nsRect& aDamageRect,
 // nsISVGChildFrame methods
 
 /**
- * Gets the rectangular region in rounded out CSS pixels that encloses the
- * rectangle after it has been transformed by aMatrix. Useful in
- * UpdateCoveredRegion/FlushDirtyRegion.
+ * Gets the rectangular region in app units (rounded out device pixels)
+ * that encloses the rectangle after it has been transformed by aMatrix.
+ * Useful in UpdateCoveredRegion/FlushDirtyRegion.
  */
 static nsRect
 GetTransformedRegion(float aX, float aY, float aWidth, float aHeight,
-                     nsIDOMSVGMatrix* aMatrix)
+                     nsIDOMSVGMatrix* aMatrix, nsPresContext *aPresContext)
 {
   float x[4], y[4];
   x[0] = aX;
@@ -221,12 +221,12 @@ GetTransformedRegion(float aX, float aY, float aWidth, float aHeight,
       ymax = y[i];
   }
  
-  return nsSVGUtils::ToBoundingPixelRect(xmin, ymin, xmax, ymax);
+  return nsSVGUtils::ToAppPixelRect(aPresContext, xmin, ymin, xmax, ymax);
 }
 
 NS_IMETHODIMP
 nsSVGForeignObjectFrame::PaintSVG(nsSVGRenderState *aContext,
-                                  nsRect *aDirtyRect)
+                                  nsIntRect *aDirtyRect)
 {
   if (IsDisabled())
     return NS_OK;
@@ -285,7 +285,8 @@ nsSVGForeignObjectFrame::PaintSVG(nsSVGRenderState *aContext,
 }
 
 nsresult
-nsSVGForeignObjectFrame::TransformPointFromOuterPx(float aX, float aY, nsPoint* aOut)
+nsSVGForeignObjectFrame::TransformPointFromOuterPx(const nsPoint &aIn,
+                                                   nsPoint* aOut)
 {
   if (mParent->GetStateBits() & NS_STATE_SVG_NONDISPLAY_CHILD)
     return NS_ERROR_FAILURE;
@@ -296,41 +297,35 @@ nsSVGForeignObjectFrame::TransformPointFromOuterPx(float aX, float aY, nsPoint*
   if (NS_FAILED(rv))
     return rv;
 
-  nsSVGUtils::TransformPoint(inverse, &aX, &aY);
-  PRInt32 appUnitsPerDevPixel = PresContext()->AppUnitsPerDevPixel();
-  *aOut = nsPoint(NSToCoordRound(aX * appUnitsPerDevPixel),
-                  NSToCoordRound(aY * appUnitsPerDevPixel));
+  float x = PresContext()->AppUnitsToDevPixels(aIn.x);
+  float y = PresContext()->AppUnitsToDevPixels(aIn.y);
+  nsSVGUtils::TransformPoint(inverse, &x, &y);
+  *aOut = nsPoint(PresContext()->DevPixelsToAppUnits(NSToIntRound(x)),
+                  PresContext()->DevPixelsToAppUnits(NSToIntRound(y)));
   return NS_OK;
 }
  
-NS_IMETHODIMP
-nsSVGForeignObjectFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
+NS_IMETHODIMP_(nsIFrame*)
+nsSVGForeignObjectFrame::GetFrameForPoint(const nsPoint &aPoint)
 {
-  *hit = nsnull;
-
   if (IsDisabled())
     return NS_OK;
 
   nsIFrame* kid = GetFirstChild(nsnull);
   if (!kid) {
-    return NS_OK;
+    return nsnull;
   }
   nsPoint pt;
-  nsresult rv = TransformPointFromOuterPx(x, y, &pt);
-  if (NS_FAILED(rv))
-    return rv;
-  *hit = nsLayoutUtils::GetFrameForPoint(kid, pt);
-  return NS_OK;
+  if (NS_FAILED(TransformPointFromOuterPx(aPoint, &pt)))
+    return nsnull;
+  return nsLayoutUtils::GetFrameForPoint(kid, pt);
 }
 
 nsPoint
 nsSVGForeignObjectFrame::TransformPointFromOuter(nsPoint aPt)
 {
   nsPoint pt(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);
-  float appUnitsPerDevPixel = PresContext()->AppUnitsPerDevPixel();
-  TransformPointFromOuterPx(aPt.x / appUnitsPerDevPixel,
-                            aPt.y / appUnitsPerDevPixel,
-                            &pt);
+  TransformPointFromOuterPx(aPt, &pt);
   return pt;
 }
 
@@ -360,7 +355,7 @@ nsSVGForeignObjectFrame::UpdateCoveredRegion()
 
   // XXXjwatt: _this_ is where we should reflow _if_ mRect.width has changed!
   // we should not unconditionally reflow in AttributeChanged
-  mRect = GetTransformedRegion(x, y, w, h, ctm);
+  mRect = GetTransformedRegion(x, y, w, h, ctm, PresContext());
 
   nsSVGUtils::UpdateFilterRegion(this);
 
@@ -684,18 +679,17 @@ nsSVGForeignObjectFrame::FlushDirtyRegion()
     return;
 
   nsCOMPtr<nsIDOMSVGMatrix> tm = GetTMIncludingOffset();
-  nsRect r = mDirtyRegion.GetBounds();
+  nsIntRect r = mDirtyRegion.GetBounds();
   r.ScaleRoundOut(1.0f / PresContext()->AppUnitsPerDevPixel());
   float x = r.x, y = r.y, w = r.width, h = r.height;
-  r = GetTransformedRegion(x, y, w, h, tm);
+  nsRect rect = GetTransformedRegion(x, y, w, h, tm, PresContext());
 
   // XXX invalidate the entire covered region
   // See bug 418063
-  r.UnionRect(r, mRect);
+  rect.UnionRect(rect, mRect);
 
-  r = nsSVGUtils::FindFilterInvalidation(this, r);
-  outerSVGFrame->InvalidateRect(r);
+  rect = nsSVGUtils::FindFilterInvalidation(this, rect);
+  outerSVGFrame->Invalidate(rect);
 
   mDirtyRegion.SetEmpty();
 }
-
diff --git a/layout/svg/base/src/nsSVGForeignObjectFrame.h b/layout/svg/base/src/nsSVGForeignObjectFrame.h
index 37fb70f9100..7970ffc96d1 100644
--- a/layout/svg/base/src/nsSVGForeignObjectFrame.h
+++ b/layout/svg/base/src/nsSVGForeignObjectFrame.h
@@ -105,8 +105,8 @@ public:
 #endif
 
   // nsISVGChildFrame interface:
-  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, nsRect *aDirtyRect);
-  NS_IMETHOD GetFrameForPointSVG(float x, float y, nsIFrame** hit);  
+  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, nsIntRect *aDirtyRect);
+  NS_IMETHOD_(nsIFrame*) GetFrameForPoint(const nsPoint &aPoint);
   NS_IMETHOD_(nsRect) GetCoveredRegion();
   NS_IMETHOD UpdateCoveredRegion();
   NS_IMETHOD InitialUpdate();
@@ -122,8 +122,8 @@ public:
 
   // foreignobject public methods
   /**
-   * @param aPt a point in the twips coordinate system of the SVG outer frame
-   * Transforms the point to a point in this frame's twips coordinate system
+   * @param aPt a point in the app unit coordinate system of the SVG outer frame
+   * Transforms the point to a point in this frame's app unit coordinate system
    */
   nsPoint TransformPointFromOuter(nsPoint aPt);
 
@@ -138,7 +138,7 @@ protected:
   void RequestReflow(nsIPresShell::IntrinsicDirty aType);
   void UpdateGraphic();
   already_AddRefed<nsIDOMSVGMatrix> GetTMIncludingOffset();
-  nsresult TransformPointFromOuterPx(float aX, float aY, nsPoint* aOut);
+  nsresult TransformPointFromOuterPx(const nsPoint &aIn, nsPoint* aOut);
   void FlushDirtyRegion();
 
   // If width or height is less than or equal to zero we must disable rendering
diff --git a/layout/svg/base/src/nsSVGGlyphFrame.cpp b/layout/svg/base/src/nsSVGGlyphFrame.cpp
index 56bed7e8e1b..ab1e719c3a7 100644
--- a/layout/svg/base/src/nsSVGGlyphFrame.cpp
+++ b/layout/svg/base/src/nsSVGGlyphFrame.cpp
@@ -297,7 +297,7 @@ nsSVGGlyphFrame::GetType() const
 // nsISVGChildFrame methods
 
 NS_IMETHODIMP
-nsSVGGlyphFrame::PaintSVG(nsSVGRenderState *aContext, nsRect *aDirtyRect)
+nsSVGGlyphFrame::PaintSVG(nsSVGRenderState *aContext, nsIntRect *aDirtyRect)
 {
   if (!GetStyleVisibility()->IsVisible())
     return NS_OK;
@@ -362,17 +362,15 @@ nsSVGGlyphFrame::PaintSVG(nsSVGRenderState *aContext, nsRect *aDirtyRect)
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsSVGGlyphFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
+NS_IMETHODIMP_(nsIFrame*)
+nsSVGGlyphFrame::GetFrameForPoint(const nsPoint &aPoint)
 {
 #ifdef DEBUG
   //printf("nsSVGGlyphFrame(%p)::GetFrameForPoint\n", this);
 #endif
-  // test for hit:
-  *hit = nsnull;
 
-  if (!mRect.Contains(nscoord(x), nscoord(y)))
-    return NS_OK;
+  if (!mRect.Contains(aPoint))
+    return nsnull;
 
   PRBool events = PR_FALSE;
   switch (GetStyleSVG()->mPointerEvents) {
@@ -405,14 +403,10 @@ nsSVGGlyphFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
       break;
   }
 
-  if (!events)
-    return NS_OK;
+  if (events && ContainsPoint(aPoint))
+    return this;
 
-  PRBool isHit = ContainsPoint(x, y);
-  if (isHit) 
-    *hit = this;
-  
-  return NS_OK;
+  return nsnull;
 }
 
 NS_IMETHODIMP_(nsRect)
@@ -448,7 +442,7 @@ nsSVGGlyphFrame::UpdateCoveredRegion()
     extent = gfxRect(0, 0, 0, 0);
   }
 
-  mRect = nsSVGUtils::ToBoundingPixelRect(extent);
+  mRect = nsSVGUtils::ToAppPixelRect(PresContext(), extent);
   return NS_OK;
 }
 
@@ -1149,7 +1143,7 @@ nsSVGGlyphFrame::NotifyGlyphMetricsChange()
 }
 
 PRBool
-nsSVGGlyphFrame::ContainsPoint(float x, float y)
+nsSVGGlyphFrame::ContainsPoint(const nsPoint &aPoint)
 {
   nsRefPtr<gfxContext> tmpCtx = MakeTmpCtx();
   SetupGlobalTransform(tmpCtx);
@@ -1165,7 +1159,8 @@ nsSVGGlyphFrame::ContainsPoint(float x, float y)
   }
 
   tmpCtx->IdentityMatrix();
-  return tmpCtx->PointInFill(gfxPoint(x, y));
+  return tmpCtx->PointInFill(gfxPoint(PresContext()->AppUnitsToGfxUnits(aPoint.x),
+                                      PresContext()->AppUnitsToGfxUnits(aPoint.y)));
 }
 
 PRBool
diff --git a/layout/svg/base/src/nsSVGGlyphFrame.h b/layout/svg/base/src/nsSVGGlyphFrame.h
index 618a3cf87bf..91e651db9fe 100644
--- a/layout/svg/base/src/nsSVGGlyphFrame.h
+++ b/layout/svg/base/src/nsSVGGlyphFrame.h
@@ -114,8 +114,8 @@ public:
 
   // nsISVGChildFrame interface:
   // These four always use the global transform, even if NS_STATE_NONDISPLAY_CHILD
-  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, nsRect *aDirtyRect);
-  NS_IMETHOD GetFrameForPointSVG(float x, float y, nsIFrame** hit);
+  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, nsIntRect *aDirtyRect);
+  NS_IMETHOD_(nsIFrame*) GetFrameForPoint(const nsPoint &aPoint);
   NS_IMETHOD UpdateCoveredRegion();
   NS_IMETHOD GetBBox(nsIDOMSVGRect **_retval);
 
@@ -207,7 +207,7 @@ protected:
                       gfxContext *aContext);
 
   void NotifyGlyphMetricsChange();
-  PRBool ContainsPoint(float x, float y);
+  PRBool ContainsPoint(const nsPoint &aPoint);
   PRBool GetGlobalTransform(gfxMatrix *aMatrix);
   void SetupGlobalTransform(gfxContext *aContext);
   nsresult GetHighlight(PRUint32 *charnum, PRUint32 *nchars,
diff --git a/layout/svg/base/src/nsSVGImageFrame.cpp b/layout/svg/base/src/nsSVGImageFrame.cpp
index a3082519974..a52e5815466 100644
--- a/layout/svg/base/src/nsSVGImageFrame.cpp
+++ b/layout/svg/base/src/nsSVGImageFrame.cpp
@@ -85,8 +85,8 @@ protected:
 
 public:
   // nsISVGChildFrame interface:
-  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, nsRect *aDirtyRect);
-  NS_IMETHOD GetFrameForPointSVG(float x, float y, nsIFrame** hit);
+  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, nsIntRect *aDirtyRect);
+  NS_IMETHOD_(nsIFrame*) GetFrameForPoint(const nsPoint &aPoint);
 
   // nsSVGPathGeometryFrame methods:
   virtual PRUint16 GetHittestMask();
@@ -224,7 +224,7 @@ nsSVGImageFrame::GetImageTransform()
 //----------------------------------------------------------------------
 // nsISVGChildFrame methods:
 NS_IMETHODIMP
-nsSVGImageFrame::PaintSVG(nsSVGRenderState *aContext, nsRect *aDirtyRect)
+nsSVGImageFrame::PaintSVG(nsSVGRenderState *aContext, nsIntRect *aDirtyRect)
 {
   nsresult rv = NS_OK;
 
@@ -296,8 +296,8 @@ nsSVGImageFrame::PaintSVG(nsSVGRenderState *aContext, nsRect *aDirtyRect)
   return rv;
 }
 
-NS_IMETHODIMP
-nsSVGImageFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
+NS_IMETHODIMP_(nsIFrame*)
+nsSVGImageFrame::GetFrameForPoint(const nsPoint &aPoint)
 {
   if (GetStyleDisplay()->IsScrollableOverflow() && mImageContainer) {
     PRInt32 nativeWidth, nativeHeight;
@@ -308,13 +308,13 @@ nsSVGImageFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
 
     if (!nsSVGUtils::HitTestRect(fini,
                                  0, 0, nativeWidth, nativeHeight,
-                                 x, y)) {
-      *hit = nsnull;
-      return NS_OK;
+                                 PresContext()->AppUnitsToDevPixels(aPoint.x),
+                                 PresContext()->AppUnitsToDevPixels(aPoint.y))) {
+      return nsnull;
     }
   }
 
-  return nsSVGPathGeometryFrame::GetFrameForPointSVG(x, y, hit);
+  return nsSVGPathGeometryFrame::GetFrameForPoint(aPoint);
 }
 
 nsIAtom *
diff --git a/layout/svg/base/src/nsSVGInnerSVGFrame.cpp b/layout/svg/base/src/nsSVGInnerSVGFrame.cpp
index c2258d49dca..e9585f6837c 100644
--- a/layout/svg/base/src/nsSVGInnerSVGFrame.cpp
+++ b/layout/svg/base/src/nsSVGInnerSVGFrame.cpp
@@ -83,12 +83,12 @@ public:
 #endif
 
   // nsISVGChildFrame interface:
-  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, nsRect *aDirtyRect);
+  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, nsIntRect *aDirtyRect);
   virtual void NotifySVGChanged(PRUint32 aFlags);
   NS_IMETHOD SetMatrixPropagation(PRBool aPropagate);
   NS_IMETHOD SetOverrideCTM(nsIDOMSVGMatrix *aCTM);
   virtual already_AddRefed<nsIDOMSVGMatrix> GetOverrideCTM();
-  NS_IMETHOD GetFrameForPointSVG(float x, float y, nsIFrame** hit);
+  NS_IMETHOD_(nsIFrame*) GetFrameForPoint(const nsPoint &aPoint);
 
   // nsSVGContainerFrame methods:
   virtual already_AddRefed<nsIDOMSVGMatrix> GetCanvasTM();
@@ -153,7 +153,7 @@ nsSVGInnerSVGFrame::GetType() const
 // nsISVGChildFrame methods
 
 NS_IMETHODIMP
-nsSVGInnerSVGFrame::PaintSVG(nsSVGRenderState *aContext, nsRect *aDirtyRect)
+nsSVGInnerSVGFrame::PaintSVG(nsSVGRenderState *aContext, nsIntRect *aDirtyRect)
 {
   gfxContextAutoSaveRestore autoSR;
 
@@ -250,8 +250,8 @@ nsSVGInnerSVGFrame::GetOverrideCTM()
   return matrix;
 }
 
-NS_IMETHODIMP
-nsSVGInnerSVGFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
+NS_IMETHODIMP_(nsIFrame*)
+nsSVGInnerSVGFrame::GetFrameForPoint(const nsPoint &aPoint)
 {
   if (GetStyleDisplay()->IsScrollableOverflow()) {
     float clipX, clipY, clipWidth, clipHeight;
@@ -266,13 +266,13 @@ nsSVGInnerSVGFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
 
     if (!nsSVGUtils::HitTestRect(clipTransform,
                                  clipX, clipY, clipWidth, clipHeight,
-                                 x, y)) {
-      *hit = nsnull;
-      return NS_OK;
+                                 PresContext()->AppUnitsToDevPixels(aPoint.x),
+                                 PresContext()->AppUnitsToDevPixels(aPoint.y))) {
+      return nsnull;
     }
   }
 
-  return nsSVGInnerSVGFrameBase::GetFrameForPointSVG(x, y, hit);
+  return nsSVGInnerSVGFrameBase::GetFrameForPoint(aPoint);
 }
 
 //----------------------------------------------------------------------
diff --git a/layout/svg/base/src/nsSVGMarkerFrame.cpp b/layout/svg/base/src/nsSVGMarkerFrame.cpp
index c9e12991539..d0ffd4f5739 100644
--- a/layout/svg/base/src/nsSVGMarkerFrame.cpp
+++ b/layout/svg/base/src/nsSVGMarkerFrame.cpp
@@ -205,7 +205,7 @@ nsSVGMarkerFrame::RegionMark(nsSVGPathGeometryFrame *aMarkedFrame,
   // has already been used in calculating the current mark region, and
   // the document has a marker reference loop.
   if (mInUse)
-    return nsRect();
+    return nsRect(0,0,0,0);
 
   AutoMarkerReferencer markerRef(this, aMarkedFrame);
 
diff --git a/layout/svg/base/src/nsSVGMaskFrame.cpp b/layout/svg/base/src/nsSVGMaskFrame.cpp
index bf2d6926eda..f6977008dcb 100644
--- a/layout/svg/base/src/nsSVGMaskFrame.cpp
+++ b/layout/svg/base/src/nsSVGMaskFrame.cpp
@@ -196,7 +196,7 @@ nsSVGMaskFrame::ComputeMaskAlpha(nsSVGRenderState *aContext,
   PRUint8 *data   = image->Data();
   PRInt32  stride = image->Stride();
 
-  nsRect rect(0, 0, surfaceSize.width, surfaceSize.height);
+  nsIntRect rect(0, 0, surfaceSize.width, surfaceSize.height);
   nsSVGUtils::UnPremultiplyImageDataAlpha(data, stride, rect);
   nsSVGUtils::ConvertImageDataToLinearRGB(data, stride, rect);
 
diff --git a/layout/svg/base/src/nsSVGOuterSVGFrame.cpp b/layout/svg/base/src/nsSVGOuterSVGFrame.cpp
index e3a7a78ad60..06344bf55d3 100644
--- a/layout/svg/base/src/nsSVGOuterSVGFrame.cpp
+++ b/layout/svg/base/src/nsSVGOuterSVGFrame.cpp
@@ -511,22 +511,12 @@ nsSVGOuterSVGFrame::AttributeChanged(PRInt32  aNameSpaceID,
 nsIFrame*
 nsSVGOuterSVGFrame::GetFrameForPoint(const nsPoint& aPoint)
 {
-  // XXX This algorithm is really bad. Because we only have a
-  // singly-linked list we have to test each and every SVG element for
-  // a hit. What we really want is a double-linked list.
-
-  float x = PresContext()->AppUnitsToDevPixels(aPoint.x);
-  float y = PresContext()->AppUnitsToDevPixels(aPoint.y);
-
   nsRect thisRect(nsPoint(0,0), GetSize());
   if (!thisRect.Contains(aPoint)) {
     return nsnull;
   }
 
-  nsIFrame* hit;
-  nsSVGUtils::HitTestChildren(this, x, y, &hit);
-
-  return hit;
+  return nsSVGUtils::HitTestChildren(this, aPoint);
 }
 
 //----------------------------------------------------------------------
@@ -644,7 +634,7 @@ nsSVGOuterSVGFrame::InvalidateCoveredRegion(nsIFrame *aFrame)
     return;
 
   nsRect rect = nsSVGUtils::FindFilterInvalidation(aFrame, svgFrame->GetCoveredRegion());
-  InvalidateRect(rect);
+  Invalidate(rect);
 }
 
 PRBool
@@ -656,25 +646,16 @@ nsSVGOuterSVGFrame::UpdateAndInvalidateCoveredRegion(nsIFrame *aFrame)
     return PR_FALSE;
 
   nsRect oldRegion = svgFrame->GetCoveredRegion();
-  InvalidateRect(nsSVGUtils::FindFilterInvalidation(aFrame, oldRegion));
+  Invalidate(nsSVGUtils::FindFilterInvalidation(aFrame, oldRegion));
   svgFrame->UpdateCoveredRegion();
   nsRect newRegion = svgFrame->GetCoveredRegion();
   if (oldRegion == newRegion)
     return PR_FALSE;
 
-  InvalidateRect(nsSVGUtils::FindFilterInvalidation(aFrame, newRegion));
+  Invalidate(nsSVGUtils::FindFilterInvalidation(aFrame, newRegion));
   return PR_TRUE;
 }
 
-void
-nsSVGOuterSVGFrame::InvalidateRect(nsRect aRect)
-{
-  if (!aRect.IsEmpty()) {
-    aRect.ScaleRoundOut(PresContext()->AppUnitsPerDevPixel());
-    Invalidate(aRect);
-  }
-}
-
 PRBool
 nsSVGOuterSVGFrame::IsRedrawSuspended()
 {
diff --git a/layout/svg/base/src/nsSVGOuterSVGFrame.h b/layout/svg/base/src/nsSVGOuterSVGFrame.h
index ce0529620ad..f077fde951d 100644
--- a/layout/svg/base/src/nsSVGOuterSVGFrame.h
+++ b/layout/svg/base/src/nsSVGOuterSVGFrame.h
@@ -95,7 +95,7 @@ public:
                         const nsHTMLReflowState*  aReflowState,
                         nsDidReflowStatus aStatus);
 
-  nsIFrame* GetFrameForPoint(const nsPoint& aPoint);
+  NS_IMETHOD_(nsIFrame*) GetFrameForPoint(const nsPoint& aPoint);
 
   NS_IMETHOD BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                               const nsRect&           aDirtyRect,
@@ -137,8 +137,6 @@ public:
   // InvalidateCoveredRegion.
   PRBool UpdateAndInvalidateCoveredRegion(nsIFrame *aFrame);
 
-  /* InvalidateRect takes a nsRect in screen pixel coordinates */
-  void InvalidateRect(nsRect aRect);
   PRBool IsRedrawSuspended();
 
   // nsISVGSVGFrame interface:
diff --git a/layout/svg/base/src/nsSVGPathGeometryFrame.cpp b/layout/svg/base/src/nsSVGPathGeometryFrame.cpp
index 1d6b613681d..a32b087667f 100644
--- a/layout/svg/base/src/nsSVGPathGeometryFrame.cpp
+++ b/layout/svg/base/src/nsSVGPathGeometryFrame.cpp
@@ -288,7 +288,7 @@ nsSVGPathGeometryFrame::GetType() const
 
 NS_IMETHODIMP
 nsSVGPathGeometryFrame::PaintSVG(nsSVGRenderState *aContext,
-                                 nsRect *aDirtyRect)
+                                 nsIntRect *aDirtyRect)
 {
   if (!GetStyleVisibility()->IsVisible())
     return NS_OK;
@@ -329,11 +329,9 @@ nsSVGPathGeometryFrame::PaintSVG(nsSVGRenderState *aContext,
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsSVGPathGeometryFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
+NS_IMETHODIMP_(nsIFrame*)
+nsSVGPathGeometryFrame::GetFrameForPoint(const nsPoint &aPoint)
 {
-  *hit = nsnull;
-
   PRUint16 fillRule, mask;
   // check if we're a clipPath - cheaper than IsClipChild(), and we shouldn't
   // get in here for other nondisplay children
@@ -344,8 +342,8 @@ nsSVGPathGeometryFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
   } else {
     mask = GetHittestMask();
     if (!mask || (!(mask & HITTEST_MASK_FORCE_TEST) &&
-                  !mRect.Contains(nscoord(x), nscoord(y))))
-      return NS_OK;
+                  !mRect.Contains(aPoint)))
+      return nsnull;
     fillRule = GetStyleSVG()->mFillRule;
   }
 
@@ -354,7 +352,9 @@ nsSVGPathGeometryFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
   gfxContext context(nsSVGUtils::GetThebesComputationalSurface());
 
   GeneratePath(&context);
-  gfxPoint devicePoint = context.DeviceToUser(gfxPoint(x, y));
+  gfxPoint userSpacePoint =
+    context.DeviceToUser(gfxPoint(PresContext()->AppUnitsToGfxUnits(aPoint.x),
+                                  PresContext()->AppUnitsToGfxUnits(aPoint.y)));
 
   if (fillRule == NS_STYLE_FILL_RULE_EVENODD)
     context.SetFillRule(gfxContext::FILL_RULE_EVEN_ODD);
@@ -362,16 +362,16 @@ nsSVGPathGeometryFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
     context.SetFillRule(gfxContext::FILL_RULE_WINDING);
 
   if (mask & HITTEST_MASK_FILL)
-    isHit = context.PointInFill(devicePoint);
+    isHit = context.PointInFill(userSpacePoint);
   if (!isHit && (mask & HITTEST_MASK_STROKE)) {
     SetupCairoStrokeHitGeometry(&context);
-    isHit = context.PointInStroke(devicePoint);
+    isHit = context.PointInStroke(userSpacePoint);
   }
 
-  if (isHit && nsSVGUtils::HitTestClip(this, x, y))
-    *hit = this;
+  if (isHit && nsSVGUtils::HitTestClip(this, aPoint))
+    return this;
 
-  return NS_OK;
+  return nsnull;
 }
 
 NS_IMETHODIMP_(nsRect)
@@ -436,13 +436,13 @@ nsSVGPathGeometryFrame::UpdateCoveredRegion()
     extent = context.GetUserStrokeExtent();
     if (!IsDegeneratePath(extent)) {
       extent = context.UserToDevice(extent);
-      mRect = nsSVGUtils::ToBoundingPixelRect(extent);
+      mRect = nsSVGUtils::ToAppPixelRect(PresContext(),extent);
     }
   } else {
     context.IdentityMatrix();
     extent = context.GetUserPathExtent();
     if (!IsDegeneratePath(extent)) {
-      mRect = nsSVGUtils::ToBoundingPixelRect(extent);
+      mRect = nsSVGUtils::ToAppPixelRect(PresContext(),extent);
     }
   }
 
diff --git a/layout/svg/base/src/nsSVGPathGeometryFrame.h b/layout/svg/base/src/nsSVGPathGeometryFrame.h
index de3f64a472b..d28390ffc59 100644
--- a/layout/svg/base/src/nsSVGPathGeometryFrame.h
+++ b/layout/svg/base/src/nsSVGPathGeometryFrame.h
@@ -103,8 +103,8 @@ public:
 
 protected:
   // nsISVGChildFrame interface:
-  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, nsRect *aDirtyRect);
-  NS_IMETHOD GetFrameForPointSVG(float x, float y, nsIFrame** hit);
+  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, nsIntRect *aDirtyRect);
+  NS_IMETHOD_(nsIFrame*) GetFrameForPoint(const nsPoint &aPoint);
   NS_IMETHOD_(nsRect) GetCoveredRegion();
   NS_IMETHOD UpdateCoveredRegion();
   NS_IMETHOD InitialUpdate();
diff --git a/layout/svg/base/src/nsSVGSwitchFrame.cpp b/layout/svg/base/src/nsSVGSwitchFrame.cpp
index 9d421b62f36..5d7f327d08c 100644
--- a/layout/svg/base/src/nsSVGSwitchFrame.cpp
+++ b/layout/svg/base/src/nsSVGSwitchFrame.cpp
@@ -66,8 +66,8 @@ public:
 #endif
 
   // nsISVGChildFrame interface:
-  NS_IMETHOD PaintSVG(nsSVGRenderState* aContext, nsRect *aDirtyRect);
-  NS_IMETHOD GetFrameForPointSVG(float aX, float aY, nsIFrame** aResult);  
+  NS_IMETHOD PaintSVG(nsSVGRenderState* aContext, nsIntRect *aDirtyRect);
+  NS_IMETHODIMP_(nsIFrame*) GetFrameForPoint(const nsPoint &aPoint);
   NS_IMETHODIMP_(nsRect) GetCoveredRegion();
   NS_IMETHOD UpdateCoveredRegion();
   NS_IMETHOD InitialUpdate();
@@ -100,7 +100,7 @@ nsSVGSwitchFrame::GetType() const
 }
 
 NS_IMETHODIMP
-nsSVGSwitchFrame::PaintSVG(nsSVGRenderState* aContext, nsRect *aDirtyRect)
+nsSVGSwitchFrame::PaintSVG(nsSVGRenderState* aContext, nsIntRect *aDirtyRect)
 {
   const nsStyleDisplay *display = mStyleContext->GetStyleDisplay();
   if (display->mOpacity == 0.0)
@@ -114,21 +114,19 @@ nsSVGSwitchFrame::PaintSVG(nsSVGRenderState* aContext, nsRect *aDirtyRect)
 }
 
 
-NS_IMETHODIMP
-nsSVGSwitchFrame::GetFrameForPointSVG(float aX, float aY, nsIFrame** aResult)
+NS_IMETHODIMP_(nsIFrame*)
+nsSVGSwitchFrame::GetFrameForPoint(const nsPoint &aPoint)
 {
-  *aResult = nsnull;
-
   nsIFrame *kid = GetActiveChildFrame();
   if (kid) {
     nsISVGChildFrame* svgFrame;
     CallQueryInterface(kid, &svgFrame);
     if (svgFrame) {
-      svgFrame->GetFrameForPointSVG(aX, aY, aResult);
+      return svgFrame->GetFrameForPoint(aPoint);
     }
   }
 
-  return NS_OK;
+  return nsnull;
 }
 
 NS_IMETHODIMP_(nsRect)
diff --git a/layout/svg/base/src/nsSVGTextFrame.cpp b/layout/svg/base/src/nsSVGTextFrame.cpp
index a4960b529cb..0dffe46cb37 100644
--- a/layout/svg/base/src/nsSVGTextFrame.cpp
+++ b/layout/svg/base/src/nsSVGTextFrame.cpp
@@ -235,19 +235,19 @@ nsSVGTextFrame::GetOverrideCTM()
 }
 
 NS_IMETHODIMP
-nsSVGTextFrame::PaintSVG(nsSVGRenderState* aContext, nsRect *aDirtyRect)
+nsSVGTextFrame::PaintSVG(nsSVGRenderState* aContext, nsIntRect *aDirtyRect)
 {
   UpdateGlyphPositioning(PR_TRUE);
   
   return nsSVGTextFrameBase::PaintSVG(aContext, aDirtyRect);
 }
 
-NS_IMETHODIMP
-nsSVGTextFrame::GetFrameForPointSVG(float x, float y, nsIFrame** hit)
+NS_IMETHODIMP_(nsIFrame*)
+nsSVGTextFrame::GetFrameForPoint(const nsPoint &aPoint)
 {
   UpdateGlyphPositioning(PR_TRUE);
   
-  return nsSVGTextFrameBase::GetFrameForPointSVG(x, y, hit);
+  return nsSVGTextFrameBase::GetFrameForPoint(aPoint);
 }
 
 NS_IMETHODIMP
diff --git a/layout/svg/base/src/nsSVGTextFrame.h b/layout/svg/base/src/nsSVGTextFrame.h
index 9ec99177a4e..39ae2afc6d4 100644
--- a/layout/svg/base/src/nsSVGTextFrame.h
+++ b/layout/svg/base/src/nsSVGTextFrame.h
@@ -83,8 +83,8 @@ public:
   NS_IMETHOD NotifyRedrawUnsuspended();
   // Override these four to ensure that UpdateGlyphPositioning is called
   // to bring glyph positions up to date
-  NS_IMETHOD PaintSVG(nsSVGRenderState* aContext, nsRect *aDirtyRect);
-  NS_IMETHOD GetFrameForPointSVG(float x, float y, nsIFrame** hit);  
+  NS_IMETHOD PaintSVG(nsSVGRenderState* aContext, nsIntRect *aDirtyRect);
+  NS_IMETHOD_(nsIFrame*) GetFrameForPoint(const nsPoint & aPoint);
   NS_IMETHOD UpdateCoveredRegion();
   NS_IMETHOD InitialUpdate();
   NS_IMETHOD GetBBox(nsIDOMSVGRect **_retval);
diff --git a/layout/svg/base/src/nsSVGUtils.cpp b/layout/svg/base/src/nsSVGUtils.cpp
index c0e3d4ebcec..aa9eb47ddbe 100644
--- a/layout/svg/base/src/nsSVGUtils.cpp
+++ b/layout/svg/base/src/nsSVGUtils.cpp
@@ -247,7 +247,7 @@ nsSVGUtils::GetFontXHeight(nsIContent *aContent)
 void
 nsSVGUtils::UnPremultiplyImageDataAlpha(PRUint8 *data, 
                                         PRInt32 stride,
-                                        const nsRect &rect)
+                                        const nsIntRect &rect)
 {
   for (PRInt32 y = rect.y; y < rect.YMost(); y++) {
     for (PRInt32 x = rect.x; x < rect.XMost(); x++) {
@@ -273,7 +273,7 @@ nsSVGUtils::UnPremultiplyImageDataAlpha(PRUint8 *data,
 void
 nsSVGUtils::PremultiplyImageDataAlpha(PRUint8 *data, 
                                       PRInt32 stride,
-                                      const nsRect &rect)
+                                      const nsIntRect &rect)
 {
   for (PRInt32 y = rect.y; y < rect.YMost(); y++) {
     for (PRInt32 x = rect.x; x < rect.XMost(); x++) {
@@ -296,7 +296,7 @@ nsSVGUtils::PremultiplyImageDataAlpha(PRUint8 *data,
 void
 nsSVGUtils::ConvertImageDataToLinearRGB(PRUint8 *data, 
                                         PRInt32 stride,
-                                        const nsRect &rect)
+                                        const nsIntRect &rect)
 {
   for (PRInt32 y = rect.y; y < rect.YMost(); y++) {
     for (PRInt32 x = rect.x; x < rect.XMost(); x++) {
@@ -315,7 +315,7 @@ nsSVGUtils::ConvertImageDataToLinearRGB(PRUint8 *data,
 void
 nsSVGUtils::ConvertImageDataFromLinearRGB(PRUint8 *data, 
                                           PRInt32 stride,
-                                          const nsRect &rect)
+                                          const nsIntRect &rect)
 {
   for (PRInt32 y = rect.y; y < rect.YMost(); y++) {
     for (PRInt32 x = rect.x; x < rect.XMost(); x++) {
@@ -919,7 +919,7 @@ nsSVGUtils::RemoveObserver(nsISupports *aObserver, nsISupports *aTarget)
 
 void
 nsSVGUtils::PaintChildWithEffects(nsSVGRenderState *aContext,
-                                  nsRect *aDirtyRect,
+                                  nsIntRect *aDirtyRect,
                                   nsIFrame *aFrame)
 {
   nsISVGChildFrame *svgChildFrame;
@@ -940,11 +940,13 @@ nsSVGUtils::PaintChildWithEffects(nsSVGRenderState *aContext,
 
   /* Check if we need to draw anything */
   if (aDirtyRect && svgChildFrame->HasValidCoveredRect()) {
+    nsRect rect = *aDirtyRect;
+    rect.ScaleRoundOut(aFrame->PresContext()->AppUnitsPerDevPixel());
     if (effectProperties.mFilter) {
-      if (!aDirtyRect->Intersects(FindFilterInvalidation(aFrame, aFrame->GetRect())))
+      if (!rect.Intersects(FindFilterInvalidation(aFrame, aFrame->GetRect())))
         return;
     } else {
-      if (!aDirtyRect->Intersects(aFrame->GetRect()))
+      if (!rect.Intersects(aFrame->GetRect()))
         return;
     }
   }
@@ -1061,7 +1063,7 @@ nsSVGUtils::UpdateEffects(nsIFrame *aFrame)
 }
 
 PRBool
-nsSVGUtils::HitTestClip(nsIFrame *aFrame, float x, float y)
+nsSVGUtils::HitTestClip(nsIFrame *aFrame, const nsPoint &aPoint)
 {
   nsSVGEffects::EffectProperties props =
     nsSVGEffects::GetEffectProperties(aFrame);
@@ -1079,12 +1081,11 @@ nsSVGUtils::HitTestClip(nsIFrame *aFrame, float x, float y)
   CallQueryInterface(aFrame, &SVGFrame);
 
   nsCOMPtr<nsIDOMSVGMatrix> matrix = GetCanvasTM(aFrame);
-  return clipPathFrame->ClipHitTest(SVGFrame, matrix, x, y);
+  return clipPathFrame->ClipHitTest(SVGFrame, matrix, aPoint);
 }
 
-void
-nsSVGUtils::HitTestChildren(nsIFrame *aFrame, float x, float y,
-                            nsIFrame **aResult)
+nsIFrame *
+nsSVGUtils::HitTestChildren(nsIFrame *aFrame, const nsPoint &aPoint)
 {
   // XXX: The frame's children are linked in a singly-linked list in document
   // order. If we were to hit test the children in this order we would need to
@@ -1098,11 +1099,11 @@ nsSVGUtils::HitTestChildren(nsIFrame *aFrame, float x, float y,
   // Note: While the child list pointers are reversed, any method which walks
   // the list would only encounter a single child!
 
-  *aResult = nsnull;
-
   nsIFrame* current = nsnull;
   nsIFrame* next = aFrame->GetFirstChild(nsnull);
 
+  nsIFrame* result = nsnull;
+
   // reverse sibling pointers
   while (next) {
     nsIFrame* temp = next->GetNextSibling();
@@ -1116,9 +1117,9 @@ nsSVGUtils::HitTestChildren(nsIFrame *aFrame, float x, float y,
     nsISVGChildFrame* SVGFrame;
     CallQueryInterface(current, &SVGFrame);
     if (SVGFrame) {
-      if (NS_SUCCEEDED(SVGFrame->GetFrameForPointSVG(x, y, aResult)) &&
-          *aResult)
-          break;
+       result = SVGFrame->GetFrameForPoint(aPoint);
+       if (result)
+         break;
     }
     // restore current frame's sibling pointer
     nsIFrame* temp = current->GetNextSibling();
@@ -1135,8 +1136,10 @@ nsSVGUtils::HitTestChildren(nsIFrame *aFrame, float x, float y,
     current = temp;
   }
 
-  if (*aResult && !HitTestClip(aFrame, x, y))
-    *aResult = nsnull;
+  if (result && !HitTestClip(aFrame, aPoint))
+    result = nsnull;
+
+  return result;
 }
 
 nsRect
@@ -1159,22 +1162,21 @@ nsSVGUtils::GetCoveredRegion(const nsFrameList &aFrames)
 }
 
 nsRect
-nsSVGUtils::ToBoundingPixelRect(double xmin, double ymin,
-                                double xmax, double ymax)
+nsSVGUtils::ToAppPixelRect(nsPresContext *aPresContext,
+                           double xmin, double ymin,
+                           double xmax, double ymax)
 {
-  return nsRect(nscoord(floor(xmin)),
-                nscoord(floor(ymin)),
-                nscoord(ceil(xmax) - floor(xmin)),
-                nscoord(ceil(ymax) - floor(ymin)));
+  return ToAppPixelRect(aPresContext,
+                        gfxRect(xmin, ymin, xmax - xmin, ymax - ymin));
 }
 
 nsRect
-nsSVGUtils::ToBoundingPixelRect(const gfxRect& rect)
+nsSVGUtils::ToAppPixelRect(nsPresContext *aPresContext, const gfxRect& rect)
 {
-  return nsRect(nscoord(floor(rect.X())),
-                nscoord(floor(rect.Y())),
-                nscoord(ceil(rect.XMost()) - floor(rect.X())),
-                nscoord(ceil(rect.YMost()) - floor(rect.Y())));
+  return nsRect(aPresContext->DevPixelsToAppUnits(NSToIntFloor(rect.X())),
+                aPresContext->DevPixelsToAppUnits(NSToIntFloor(rect.Y())),
+                aPresContext->DevPixelsToAppUnits(NSToIntCeil(rect.XMost()) - NSToIntFloor(rect.X())),
+                aPresContext->DevPixelsToAppUnits(NSToIntCeil(rect.YMost()) - NSToIntFloor(rect.Y())));
 }
 
 gfxIntSize
diff --git a/layout/svg/base/src/nsSVGUtils.h b/layout/svg/base/src/nsSVGUtils.h
index 66cdb37549c..561f42b438d 100644
--- a/layout/svg/base/src/nsSVGUtils.h
+++ b/layout/svg/base/src/nsSVGUtils.h
@@ -203,25 +203,25 @@ public:
    */
   static void UnPremultiplyImageDataAlpha(PRUint8 *data, 
                                           PRInt32 stride, 
-                                          const nsRect &rect);
+                                          const nsIntRect &rect);
   /*
    * Converts image data from unpremultipled to premultiplied alpha
    */
   static void PremultiplyImageDataAlpha(PRUint8 *data, 
                                         PRInt32 stride, 
-                                        const nsRect &rect);
+                                        const nsIntRect &rect);
   /*
    * Converts image data from premultiplied sRGB to Linear RGB
    */
   static void ConvertImageDataToLinearRGB(PRUint8 *data, 
                                           PRInt32 stride, 
-                                          const nsRect &rect);
+                                          const nsIntRect &rect);
   /*
    * Converts image data from LinearRGB to premultiplied sRGB
    */
   static void ConvertImageDataFromLinearRGB(PRUint8 *data, 
                                             PRInt32 stride, 
-                                            const nsRect &rect);
+                                            const nsIntRect &rect);
 
   /*
    * Report a localized error message to the error console.
@@ -322,7 +322,7 @@ public:
 
   /**
    * Get the covered region for a frame. Return null if it's not an SVG frame.
-   * @param aRect gets a rectangle in *pixels*
+   * @param aRect gets a rectangle in app units
    * @return the outer SVG frame which aRect is relative to
    */
   static nsIFrame*
@@ -341,7 +341,7 @@ public:
    * redrawn, in frame offset pixel coordinates */
   static void
   PaintChildWithEffects(nsSVGRenderState *aContext,
-                        nsRect *aDirtyRect,
+                        nsIntRect *aDirtyRect,
                         nsIFrame *aFrame);
 
   /**
@@ -352,16 +352,14 @@ public:
   UpdateEffects(nsIFrame *aFrame);
 
   /* Hit testing - check if point hits the clipPath of indicated
-   * frame.  (x,y) are specified in device pixels relative to the
-   * origin of the outer svg frame.  Returns true if no clipPath
-   * set. */
+   * frame.  Returns true if no clipPath set. */
   static PRBool
-  HitTestClip(nsIFrame *aFrame, float x, float y);
-
-  /* Hit testing - check if point hits any children of frame. */
+  HitTestClip(nsIFrame *aFrame, const nsPoint &aPoint);
   
-  static void
-  HitTestChildren(nsIFrame *aFrame, float x, float y, nsIFrame **aResult);
+  /* Hit testing - check if point hits any children of frame. */
+
+  static nsIFrame *
+  HitTestChildren(nsIFrame *aFrame, const nsPoint &aPoint);
 
   /* Add observation of an nsISVGValue to an nsISVGValueObserver */
   static void
@@ -390,12 +388,13 @@ public:
   GetCoveredRegion(const nsFrameList &aFrames);
 
   /*
-   * Inflate a floating-point rect to a nsRect
+   * Convert a rect from device pixel units to app pixel units by inflation.
    */
   static nsRect
-  ToBoundingPixelRect(double xmin, double ymin, double xmax, double ymax);
+  ToAppPixelRect(nsPresContext *aPresContext,
+                 double xmin, double ymin, double xmax, double ymax);
   static nsRect
-  ToBoundingPixelRect(const gfxRect& rect);
+  ToAppPixelRect(nsPresContext *aPresContext, const gfxRect& rect);
 
   /*
    * Convert a surface size to an integer for use by thebes