diff --git a/mozilla/content/base/src/nsStyleContext.cpp b/mozilla/content/base/src/nsStyleContext.cpp
index cd3514441f9..a520fa357f4 100644
--- a/mozilla/content/base/src/nsStyleContext.cpp
+++ b/mozilla/content/base/src/nsStyleContext.cpp
@@ -245,9 +245,9 @@ void nsStyleSpacing::CalcPaddingFor(const nsIFrame* aFrame, nsMargin& aPadding)
 }
 
 static const nscoord kBorderWidths[3] = 
-  { NS_POINTS_TO_TWIPS_INT(1), 
-    NS_POINTS_TO_TWIPS_INT(3), 
-    NS_POINTS_TO_TWIPS_INT(5) };
+  { NSIntPointsToTwips(1), 
+    NSIntPointsToTwips(3), 
+    NSIntPointsToTwips(5) };
 
 void nsStyleSpacing::CalcBorderFor(const nsIFrame* aFrame, nsMargin& aBorder) const
 {
diff --git a/mozilla/content/events/src/nsDOMEvent.cpp b/mozilla/content/events/src/nsDOMEvent.cpp
index 97e38f75804..81bb727b7be 100644
--- a/mozilla/content/events/src/nsDOMEvent.cpp
+++ b/mozilla/content/events/src/nsDOMEvent.cpp
@@ -128,7 +128,7 @@ NS_METHOD nsDOMEvent::SetScreenY(PRInt32 aScreenY)
 
 NS_METHOD nsDOMEvent::GetClientX(PRInt32* aClientX)
 {
-  *aClientX = NS_TO_INT_ROUND(mEvent->point.x * mPresContext->GetTwipsToPixels());
+  *aClientX = NSTwipsToIntPixels(mEvent->point.x, mPresContext->GetTwipsToPixels());
   return NS_OK;
 }
 
@@ -139,7 +139,7 @@ NS_METHOD nsDOMEvent::SetClientX(PRInt32 aClientX)
 
 NS_METHOD nsDOMEvent::GetClientY(PRInt32* aClientY)
 {
-  *aClientY = NS_TO_INT_ROUND(mEvent->point.y * mPresContext->GetTwipsToPixels());
+  *aClientY = NSTwipsToIntPixels(mEvent->point.y, mPresContext->GetTwipsToPixels());
   return NS_OK;
 }
 
diff --git a/mozilla/content/html/document/src/nsHTMLContentSink.cpp b/mozilla/content/html/document/src/nsHTMLContentSink.cpp
index cf1b6c98d79..d7d83c3e9f2 100644
--- a/mozilla/content/html/document/src/nsHTMLContentSink.cpp
+++ b/mozilla/content/html/document/src/nsHTMLContentSink.cpp
@@ -1158,7 +1158,7 @@ HTMLContentSink::ScrollToRef()
 #if 0
 nsIPresContext* cx = shell->GetPresContext();
 float t2p = cx->GetTwipsToPixels();
-printf("x=%d y=%d\n", nscoord(x * t2p), nscoord(y * t2p));
+printf("x=%d y=%d\n", NSTwipsToIntPixels(x, t2p), NSTwipsToIntPixels(y, t2p));
 NS_RELEASE(cx);
 #endif
                 sview->SetScrollPreference(mOriginalScrollPreference);
diff --git a/mozilla/content/html/style/src/nsCSSDeclaration.cpp b/mozilla/content/html/style/src/nsCSSDeclaration.cpp
index 38f4f48d504..9043f5df4c3 100644
--- a/mozilla/content/html/style/src/nsCSSDeclaration.cpp
+++ b/mozilla/content/html/style/src/nsCSSDeclaration.cpp
@@ -322,29 +322,29 @@ nscoord nsCSSValue::GetLengthTwips(void) const
   if (IsFixedLengthUnit()) {
     switch (mUnit) {
     case eCSSUnit_Inch:        
-      return (nscoord)NS_INCHES_TO_TWIPS(mValue.mFloat);
+      return NS_INCHES_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Foot:        
-      return (nscoord)NS_FEET_TO_TWIPS(mValue.mFloat);
+      return NS_FEET_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Mile:        
-      return (nscoord)NS_MILES_TO_TWIPS(mValue.mFloat);
+      return NS_MILES_TO_TWIPS(mValue.mFloat);
 
     case eCSSUnit_Millimeter:
-      return (nscoord)NS_MILLIMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_MILLIMETERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Centimeter:
-      return (nscoord)NS_CENTIMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_CENTIMETERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Meter:
-      return (nscoord)NS_METERS_TO_TWIPS(mValue.mFloat);
+      return NS_METERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Kilometer:
-      return (nscoord)NS_KILOMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_KILOMETERS_TO_TWIPS(mValue.mFloat);
 
     case eCSSUnit_Point:
-      return (nscoord)NS_POINTS_TO_TWIPS_FLOAT(mValue.mFloat);
+      return NSFloatPointsToTwips(mValue.mFloat);
     case eCSSUnit_Pica:
-      return (nscoord)NS_PICAS_TO_TWIPS(mValue.mFloat);
+      return NS_PICAS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Didot:
-      return (nscoord)NS_DIDOTS_TO_TWIPS(mValue.mFloat);
+      return NS_DIDOTS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Cicero:
-      return (nscoord)NS_CICEROS_TO_TWIPS(mValue.mFloat);
+      return NS_CICEROS_TO_TWIPS(mValue.mFloat);
     }
   }
   return 0;
diff --git a/mozilla/content/html/style/src/nsCSSStruct.cpp b/mozilla/content/html/style/src/nsCSSStruct.cpp
index 38f4f48d504..9043f5df4c3 100644
--- a/mozilla/content/html/style/src/nsCSSStruct.cpp
+++ b/mozilla/content/html/style/src/nsCSSStruct.cpp
@@ -322,29 +322,29 @@ nscoord nsCSSValue::GetLengthTwips(void) const
   if (IsFixedLengthUnit()) {
     switch (mUnit) {
     case eCSSUnit_Inch:        
-      return (nscoord)NS_INCHES_TO_TWIPS(mValue.mFloat);
+      return NS_INCHES_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Foot:        
-      return (nscoord)NS_FEET_TO_TWIPS(mValue.mFloat);
+      return NS_FEET_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Mile:        
-      return (nscoord)NS_MILES_TO_TWIPS(mValue.mFloat);
+      return NS_MILES_TO_TWIPS(mValue.mFloat);
 
     case eCSSUnit_Millimeter:
-      return (nscoord)NS_MILLIMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_MILLIMETERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Centimeter:
-      return (nscoord)NS_CENTIMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_CENTIMETERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Meter:
-      return (nscoord)NS_METERS_TO_TWIPS(mValue.mFloat);
+      return NS_METERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Kilometer:
-      return (nscoord)NS_KILOMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_KILOMETERS_TO_TWIPS(mValue.mFloat);
 
     case eCSSUnit_Point:
-      return (nscoord)NS_POINTS_TO_TWIPS_FLOAT(mValue.mFloat);
+      return NSFloatPointsToTwips(mValue.mFloat);
     case eCSSUnit_Pica:
-      return (nscoord)NS_PICAS_TO_TWIPS(mValue.mFloat);
+      return NS_PICAS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Didot:
-      return (nscoord)NS_DIDOTS_TO_TWIPS(mValue.mFloat);
+      return NS_DIDOTS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Cicero:
-      return (nscoord)NS_CICEROS_TO_TWIPS(mValue.mFloat);
+      return NS_CICEROS_TO_TWIPS(mValue.mFloat);
     }
   }
   return 0;
diff --git a/mozilla/content/html/style/src/nsCSSStyleRule.cpp b/mozilla/content/html/style/src/nsCSSStyleRule.cpp
index 7eb2e08fd41..3e2b6f680c0 100644
--- a/mozilla/content/html/style/src/nsCSSStyleRule.cpp
+++ b/mozilla/content/html/style/src/nsCSSStyleRule.cpp
@@ -438,7 +438,7 @@ nscoord CSSStyleRuleImpl::CalcLength(const nsCSSValue& aValue,
       return ((aFont->mFont.size / 3) * 2); // XXX HACK!
 
     case eCSSUnit_Pixel:
-      return (nscoord)(aPresContext->GetPixelsToTwips() * aValue.GetFloatValue());
+      return NSFloatPixelsToTwips(aValue.GetFloatValue(), aPresContext->GetPixelsToTwips());
   }
   return 0;
 }
diff --git a/mozilla/content/html/style/src/nsStyleUtil.cpp b/mozilla/content/html/style/src/nsStyleUtil.cpp
index 50e443f4b25..1ab34d8949a 100644
--- a/mozilla/content/html/style/src/nsStyleUtil.cpp
+++ b/mozilla/content/html/style/src/nsStyleUtil.cpp
@@ -48,7 +48,7 @@ float nsStyleUtil::GetScalingFactor(PRInt32 aScaler)
     scale *= mult;
   }
 
-  return scale;
+  return (float)scale;
 }
 
 /*
diff --git a/mozilla/content/shared/src/nsStyleUtil.cpp b/mozilla/content/shared/src/nsStyleUtil.cpp
index 50e443f4b25..1ab34d8949a 100644
--- a/mozilla/content/shared/src/nsStyleUtil.cpp
+++ b/mozilla/content/shared/src/nsStyleUtil.cpp
@@ -48,7 +48,7 @@ float nsStyleUtil::GetScalingFactor(PRInt32 aScaler)
     scale *= mult;
   }
 
-  return scale;
+  return (float)scale;
 }
 
 /*
diff --git a/mozilla/gfx/src/mac/nsDeviceContextMac.cpp b/mozilla/gfx/src/mac/nsDeviceContextMac.cpp
index eee1a17dc5d..2d041319d8a 100644
--- a/mozilla/gfx/src/mac/nsDeviceContextMac.cpp
+++ b/mozilla/gfx/src/mac/nsDeviceContextMac.cpp
@@ -109,7 +109,7 @@ nsresult nsDeviceContextMac :: Init(nsNativeWidget aNativeWidget)
   {
     mTwipsToPixels = (((float)::XDisplayWidth(XtDisplay((Widget)mNativeWidget), DefaultScreen(XtDisplay((Widget)mNativeWidget)))) /
   		    ((float)::XDisplayWidthMM(XtDisplay((Widget)mNativeWidget),DefaultScreen(XtDisplay((Widget)mNativeWidget)) )) * 25.4) / 
-      NS_POINTS_TO_TWIPS_FLOAT(72.0f);
+      (float)NSIntPointsToTwips(72);
     
     mPixelsToTwips = 1.0f / mTwipsToPixels;
   }*/
diff --git a/mozilla/gfx/src/mac/nsFontMetricsMac.cpp b/mozilla/gfx/src/mac/nsFontMetricsMac.cpp
index 62b4a799b01..59d14a31f7b 100644
--- a/mozilla/gfx/src/mac/nsFontMetricsMac.cpp
+++ b/mozilla/gfx/src/mac/nsFontMetricsMac.cpp
@@ -54,7 +54,7 @@ nsresult nsFontMetricsMac :: Init(const nsFont& aFont, nsIDeviceContext* aCX)
   int         numnames = 0;
   char        altitalicization = 0;
   XFontStruct *fonts;
-  PRInt32     dpi = NS_TO_INT_ROUND(aCX->GetTwipsToDevUnits() * 1440);
+  PRInt32     dpi = NSToIntRound(aCX->GetTwipsToDevUnits() * 1440);
   Display     *dpy = XtDisplay((Widget)aCX->GetNativeWidget());
 
   if (nsnull == wildstring)
@@ -166,7 +166,7 @@ nsresult nsFontMetricsMac :: Init(const nsFont& aFont, nsIDeviceContext* aCX)
 /*char * nsFontMetricsMac::PickAppropriateSize(char **names, XFontStruct *fonts, int cnt, nscoord desired)
 {
   int         idx;
-  PRInt32     desiredpix = NS_TO_INT_ROUND(mContext->GetAppUnitsToDevUnits() * desired);
+  PRInt32     desiredpix = NSToIntRound(mContext->GetAppUnitsToDevUnits() * desired);
   XFontStruct *curfont;
   PRInt32     closestmin = -1, minidx;
 
diff --git a/mozilla/gfx/src/mac/nsRenderingContextMac.cpp b/mozilla/gfx/src/mac/nsRenderingContextMac.cpp
index 9e6625997f6..84e23309c13 100644
--- a/mozilla/gfx/src/mac/nsRenderingContextMac.cpp
+++ b/mozilla/gfx/src/mac/nsRenderingContextMac.cpp
@@ -752,8 +752,8 @@ void nsRenderingContextMac :: DrawArc(nscoord aX, nscoord aY, nscoord aWidth, ns
   ::XDrawArc(mRenderingSurface->display, 
 	     mRenderingSurface->drawable,
 	     mRenderingSurface->gc,
-	     x,y,w,h, NS_TO_INT_ROUND(aStartAngle * 64.0f),
-             NS_TO_INT_ROUND(aEndAngle * 64.0f));
+	     x,y,w,h, NSToIntRound(aStartAngle * 64.0f),
+             NSToIntRound(aEndAngle * 64.0f));
 }
 
 void nsRenderingContextMac :: FillArc(const nsRect& aRect,
@@ -777,8 +777,8 @@ void nsRenderingContextMac :: FillArc(nscoord aX, nscoord aY, nscoord aWidth, ns
   ::XFillArc(mRenderingSurface->display, 
 	     mRenderingSurface->drawable,
 	     mRenderingSurface->gc,
-	     x,y,w,h, NS_TO_INT_ROUND(aStartAngle * 64.0f),
-             NS_TO_INT_ROUND(aEndAngle * 64.0f));
+	     x,y,w,h, NSToIntRound(aStartAngle * 64.0f),
+             NSToIntRound(aEndAngle * 64.0f));
 }
 
 void nsRenderingContextMac :: DrawString(const char *aString, PRUint32 aLength,
@@ -875,8 +875,8 @@ void nsRenderingContextMac :: DrawString(const nsString& aString,
 void nsRenderingContextMac :: DrawImage(nsIImage *aImage, nscoord aX, nscoord aY)
 {
   nscoord width,height;
-  width = NS_TO_INT_ROUND(mP2T * aImage->GetWidth());
-  height = NS_TO_INT_ROUND(mP2T * aImage->GetHeight());
+  width = NSToCoordRound(mP2T * aImage->GetWidth());
+  height = NSToCoordRound(mP2T * aImage->GetHeight());
   
   this->DrawImage(aImage,aX,aY,width,height);8?
 }
diff --git a/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp b/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp
index 6a2effcccb6..332b4abdc73 100644
--- a/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp
+++ b/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp
@@ -106,7 +106,7 @@ nsresult nsDeviceContextUnix :: Init(nsNativeWidget aNativeWidget)
   {
     mTwipsToPixels = (((float)::XDisplayWidth(XtDisplay((Widget)mNativeWidget), DefaultScreen(XtDisplay((Widget)mNativeWidget)))) /
   		    ((float)::XDisplayWidthMM(XtDisplay((Widget)mNativeWidget),DefaultScreen(XtDisplay((Widget)mNativeWidget)) )) * 25.4) / 
-      NS_POINTS_TO_TWIPS_FLOAT(72.0f);
+      (float)NSIntPointsToTwips(72);
     
     mPixelsToTwips = 1.0f / mTwipsToPixels;
   }
diff --git a/mozilla/gfx/src/motif/nsFontMetricsUnix.cpp b/mozilla/gfx/src/motif/nsFontMetricsUnix.cpp
index f5d8796d373..3db54a0edaf 100644
--- a/mozilla/gfx/src/motif/nsFontMetricsUnix.cpp
+++ b/mozilla/gfx/src/motif/nsFontMetricsUnix.cpp
@@ -63,7 +63,7 @@ nsresult nsFontMetricsUnix :: Init(const nsFont& aFont, nsIDeviceContext* aCX)
   int         numnames = 0;
   char        altitalicization = 0;
   XFontStruct *fonts;
-  PRInt32     dpi = NS_TO_INT_ROUND(aCX->GetTwipsToDevUnits() * 1440);
+  PRInt32     dpi = NSToIntRound(aCX->GetTwipsToDevUnits() * 1440);
   Display     *dpy = XtDisplay((Widget)aCX->GetNativeWidget());
 
   if (nsnull == wildstring)
@@ -175,7 +175,7 @@ nsresult nsFontMetricsUnix :: Init(const nsFont& aFont, nsIDeviceContext* aCX)
 char * nsFontMetricsUnix::PickAppropriateSize(char **names, XFontStruct *fonts, int cnt, nscoord desired)
 {
   int         idx;
-  PRInt32     desiredpix = NS_TO_INT_ROUND(mContext->GetAppUnitsToDevUnits() * desired);
+  PRInt32     desiredpix = NSToIntRound(mContext->GetAppUnitsToDevUnits() * desired);
   XFontStruct *curfont;
   PRInt32     closestmin = -1, minidx;
 
diff --git a/mozilla/gfx/src/motif/nsRenderingContextUnix.cpp b/mozilla/gfx/src/motif/nsRenderingContextUnix.cpp
index 88c161413c6..2b674d40d6e 100644
--- a/mozilla/gfx/src/motif/nsRenderingContextUnix.cpp
+++ b/mozilla/gfx/src/motif/nsRenderingContextUnix.cpp
@@ -899,8 +899,8 @@ void nsRenderingContextUnix :: DrawArc(nscoord aX, nscoord aY, nscoord aWidth, n
   ::XDrawArc(mRenderingSurface->display, 
 	     mRenderingSurface->drawable,
 	     mRenderingSurface->gc,
-	     x,y,w,h, NS_TO_INT_ROUND(aStartAngle * 64.0f),
-             NS_TO_INT_ROUND(aEndAngle * 64.0f));
+	     x,y,w,h, NSToIntRound(aStartAngle * 64.0f),
+             NSToIntRound(aEndAngle * 64.0f));
 }
 
 void nsRenderingContextUnix :: FillArc(const nsRect& aRect,
@@ -924,8 +924,8 @@ void nsRenderingContextUnix :: FillArc(nscoord aX, nscoord aY, nscoord aWidth, n
   ::XFillArc(mRenderingSurface->display, 
 	     mRenderingSurface->drawable,
 	     mRenderingSurface->gc,
-	     x,y,w,h, NS_TO_INT_ROUND(aStartAngle * 64.0f),
-             NS_TO_INT_ROUND(aEndAngle * 64.0f));
+	     x,y,w,h, NSToIntRound(aStartAngle * 64.0f),
+             NSToIntRound(aEndAngle * 64.0f));
 }
 
 void nsRenderingContextUnix :: DrawString(const char *aString, PRUint32 aLength,
@@ -1022,8 +1022,8 @@ void nsRenderingContextUnix :: DrawString(const nsString& aString,
 void nsRenderingContextUnix :: DrawImage(nsIImage *aImage, nscoord aX, nscoord aY)
 {
   nscoord width,height;
-  width = NS_TO_INT_ROUND(mP2T * aImage->GetWidth());
-  height = NS_TO_INT_ROUND(mP2T * aImage->GetHeight());
+  width = NSToCoordRound(mP2T * aImage->GetWidth());
+  height = NSToCoordRound(mP2T * aImage->GetHeight());
   
   this->DrawImage(aImage,aX,aY,width,height);
 }
diff --git a/mozilla/gfx/src/nsRect.cpp b/mozilla/gfx/src/nsRect.cpp
index 06867b7a55b..313d3aaa3e2 100644
--- a/mozilla/gfx/src/nsRect.cpp
+++ b/mozilla/gfx/src/nsRect.cpp
@@ -152,6 +152,30 @@ void nsRect::Deflate(const nsMargin &aMargin)
   height -= aMargin.top + aMargin.bottom;
 }
 
+// scale the rect but round to smallest containing rect
+nsRect& nsRect::ScaleRoundOut(const float aScale) 
+{
+  nscoord right = NSToCoordCeil(float(x + width) * aScale);
+  nscoord bottom = NSToCoordCeil(float(y + height) * aScale);
+  x = NSToCoordFloor(float(x) * aScale);
+  y = NSToCoordFloor(float(y) * aScale);
+  width = (right - x);
+  height = (bottom - y);
+  return *this;
+}
+
+// scale the rect but round to largest contained rect
+nsRect& nsRect::ScaleRoundIn(const float aScale) 
+{
+  nscoord right = NSToCoordFloor(float(x + width) * aScale);
+  nscoord bottom = NSToCoordFloor(float(y + height) * aScale);
+  x = NSToCoordCeil(float(x) * aScale);
+  y = NSToCoordCeil(float(y) * aScale);
+  width = (right - x);
+  height = (bottom - y);
+  return *this;
+}
+
 // Diagnostics
 
 FILE* operator<<(FILE* out, const nsRect& rect)
@@ -160,13 +184,13 @@ FILE* operator<<(FILE* out, const nsRect& rect)
 
   // Output the coordinates in fractional points so they're easier to read
   tmp.Append("{");
-  tmp.Append(NS_TWIPS_TO_POINTS_FLOAT(rect.x));
+  tmp.Append(NSTwipsToFloatPoints(rect.x));
   tmp.Append(", ");
-  tmp.Append(NS_TWIPS_TO_POINTS_FLOAT(rect.y));
+  tmp.Append(NSTwipsToFloatPoints(rect.y));
   tmp.Append(", ");
-  tmp.Append(NS_TWIPS_TO_POINTS_FLOAT(rect.width));
+  tmp.Append(NSTwipsToFloatPoints(rect.width));
   tmp.Append(", ");
-  tmp.Append(NS_TWIPS_TO_POINTS_FLOAT(rect.height));
+  tmp.Append(NSTwipsToFloatPoints(rect.height));
   tmp.Append("}");
   fputs(tmp, out);
   return out;
diff --git a/mozilla/gfx/src/nsRect.h b/mozilla/gfx/src/nsRect.h
index 05b214a6f49..ee6beadc6f2 100644
--- a/mozilla/gfx/src/nsRect.h
+++ b/mozilla/gfx/src/nsRect.h
@@ -112,12 +112,15 @@ struct NS_GFX nsRect {
   nsRect& operator+=(const nsPoint& aPoint) {x += aPoint.x; y += aPoint.y; return *this;}
   nsRect& operator-=(const nsPoint& aPoint) {x -= aPoint.x; y -= aPoint.y; return *this;}
 
-  nsRect& operator*=(const float aScale) {x = NS_TO_INT_ROUND(x * aScale); 
-                                          y = NS_TO_INT_ROUND(y * aScale); 
-                                          width = NS_TO_INT_ROUND(width * aScale); 
-                                          height = NS_TO_INT_ROUND(height * aScale); 
+  nsRect& operator*=(const float aScale) {x = NSToCoordRound(x * aScale); 
+                                          y = NSToCoordRound(y * aScale); 
+                                          width = NSToCoordRound(width * aScale); 
+                                          height = NSToCoordRound(height * aScale); 
                                           return *this;}
 
+  nsRect& ScaleRoundOut(const float aScale);
+  nsRect& ScaleRoundIn(const float aScale);
+
   // Helper methods for computing the extents
   nscoord XMost() const {return x + width;}
   nscoord YMost() const {return y + height;}
diff --git a/mozilla/gfx/src/nsTransform2D.cpp b/mozilla/gfx/src/nsTransform2D.cpp
index 59633af4fac..4682f1b2205 100644
--- a/mozilla/gfx/src/nsTransform2D.cpp
+++ b/mozilla/gfx/src/nsTransform2D.cpp
@@ -279,8 +279,8 @@ void nsTransform2D :: TransformNoXLateCoord(nscoord *ptX, nscoord *ptY)
       break;
 
     case MG_2DSCALE:
-      *ptX = NS_TO_INT_ROUND(*ptX * m00);
-      *ptY = NS_TO_INT_ROUND(*ptY * m11);
+      *ptX = NSToCoordRound(*ptX * m00);
+      *ptY = NSToCoordRound(*ptY * m11);
       break;
 
     default:
@@ -288,8 +288,8 @@ void nsTransform2D :: TransformNoXLateCoord(nscoord *ptX, nscoord *ptY)
       x = (float)*ptX;
       y = (float)*ptY;
 
-      *ptX = NS_TO_INT_ROUND(x * m00 + y * m10);
-      *ptY = NS_TO_INT_ROUND(x * m01 + y * m11);
+      *ptX = NSToCoordRound(x * m00 + y * m10);
+      *ptY = NSToCoordRound(x * m01 + y * m11);
 
       break;
   }
@@ -350,27 +350,27 @@ void nsTransform2D :: TransformCoord(nscoord *ptX, nscoord *ptY)
       break;
 
     case MG_2DTRANSLATION:
-      *ptX += NS_TO_INT_ROUND(m20);
-      *ptY += NS_TO_INT_ROUND(m21);
+      *ptX += NSToCoordRound(m20);
+      *ptY += NSToCoordRound(m21);
       break;
 
     case MG_2DSCALE:
-      *ptX = NS_TO_INT_ROUND(*ptX * m00);
-      *ptY = NS_TO_INT_ROUND(*ptY * m11);
+      *ptX = NSToCoordRound(*ptX * m00);
+      *ptY = NSToCoordRound(*ptY * m11);
       break;
 
     case MG_2DGENERAL:
       x = (float)*ptX;
       y = (float)*ptY;
 
-      *ptX = NS_TO_INT_ROUND(x * m00 + y * m10);
-      *ptY = NS_TO_INT_ROUND(x * m01 + y * m11);
+      *ptX = NSToCoordRound(x * m00 + y * m10);
+      *ptY = NSToCoordRound(x * m01 + y * m11);
 
       break;
 
     case MG_2DSCALE | MG_2DTRANSLATION:
-      *ptX = NS_TO_INT_ROUND(*ptX * m00 + m20);
-      *ptY = NS_TO_INT_ROUND(*ptY * m11 + m21);
+      *ptX = NSToCoordRound(*ptX * m00 + m20);
+      *ptY = NSToCoordRound(*ptY * m11 + m21);
       break;
 
     default:
@@ -378,8 +378,8 @@ void nsTransform2D :: TransformCoord(nscoord *ptX, nscoord *ptY)
       x = (float)*ptX;
       y = (float)*ptY;
 
-      *ptX = NS_TO_INT_ROUND(x * m00 + y * m10 + m20);
-      *ptY = NS_TO_INT_ROUND(x * m01 + y * m11 + m21);
+      *ptX = NSToCoordRound(x * m00 + y * m10 + m20);
+      *ptY = NSToCoordRound(x * m01 + y * m11 + m21);
 
       break;
   }
@@ -456,37 +456,37 @@ void nsTransform2D :: TransformCoord(nscoord *aX, nscoord *aY, nscoord *aWidth,
       break;
 
     case MG_2DTRANSLATION:
-      *aX += NS_TO_INT_ROUND(m20);
-      *aY += NS_TO_INT_ROUND(m21);
+      *aX += NSToCoordRound(m20);
+      *aY += NSToCoordRound(m21);
       break;
 
     case MG_2DSCALE:
-      *aX = NS_TO_INT_ROUND(*aX * m00);
-      *aY = NS_TO_INT_ROUND(*aY * m11);
-      *aWidth = NS_TO_INT_ROUND(*aWidth * m00);
-      *aHeight = NS_TO_INT_ROUND(*aHeight * m11);
+      *aX = NSToCoordRound(*aX * m00);
+      *aY = NSToCoordRound(*aY * m11);
+      *aWidth = NSToCoordRound(*aWidth * m00);
+      *aHeight = NSToCoordRound(*aHeight * m11);
       break;
 
     case MG_2DGENERAL:
       x = (float)*aX;
       y = (float)*aY;
 
-      *aX = NS_TO_INT_ROUND(x * m00 + y * m10);
-      *aY = NS_TO_INT_ROUND(x * m01 + y * m11);
+      *aX = NSToCoordRound(x * m00 + y * m10);
+      *aY = NSToCoordRound(x * m01 + y * m11);
 
       x = (float)*aWidth;
       y = (float)*aHeight;
 
-      *aHeight = NS_TO_INT_ROUND(x * m00 + y * m10);
-      *aHeight = NS_TO_INT_ROUND(x * m01 + y * m11);
+      *aHeight = NSToCoordRound(x * m00 + y * m10);
+      *aHeight = NSToCoordRound(x * m01 + y * m11);
 
       break;
 
     case MG_2DSCALE | MG_2DTRANSLATION:
-      *aX = NS_TO_INT_ROUND(*aX * m00 + m20);
-      *aY = NS_TO_INT_ROUND(*aY * m11 + m21);
-      *aWidth = NS_TO_INT_ROUND(*aWidth * m00);
-      *aHeight = NS_TO_INT_ROUND(*aHeight * m11);
+      *aX = NSToCoordRound(*aX * m00 + m20);
+      *aY = NSToCoordRound(*aY * m11 + m21);
+      *aWidth = NSToCoordRound(*aWidth * m00);
+      *aHeight = NSToCoordRound(*aHeight * m11);
       break;
 
     default:
@@ -494,14 +494,14 @@ void nsTransform2D :: TransformCoord(nscoord *aX, nscoord *aY, nscoord *aWidth,
       x = (float)*aX;
       y = (float)*aY;
 
-      *aX = NS_TO_INT_ROUND(x * m00 + y * m10 + m20);
-      *aY = NS_TO_INT_ROUND(x * m01 + y * m11 + m21);
+      *aX = NSToCoordRound(x * m00 + y * m10 + m20);
+      *aY = NSToCoordRound(x * m01 + y * m11 + m21);
 
       x = (float)*aWidth;
       y = (float)*aHeight;
 
-      *aWidth = NS_TO_INT_ROUND(x * m00 + y * m10);
-      *aHeight = NS_TO_INT_ROUND(x * m01 + y * m11);
+      *aWidth = NSToCoordRound(x * m00 + y * m10);
+      *aHeight = NSToCoordRound(x * m01 + y * m11);
 
       break;
   }
diff --git a/mozilla/gfx/src/nsTransform2D.h b/mozilla/gfx/src/nsTransform2D.h
index 523158a1ab0..145d8fbe957 100644
--- a/mozilla/gfx/src/nsTransform2D.h
+++ b/mozilla/gfx/src/nsTransform2D.h
@@ -98,7 +98,7 @@ public:
   **/
 
   void GetTranslation(float *ptX, float *ptY) { *ptX = m20; *ptY = m21; }
-  void GetTranslationCoord(nscoord *ptX, nscoord *ptY) { *ptX = NS_TO_INT_ROUND(m20); *ptY = NS_TO_INT_ROUND(m21); }
+  void GetTranslationCoord(nscoord *ptX, nscoord *ptY) { *ptX = NSToCoordRound(m20); *ptY = NSToCoordRound(m21); }
 
  /**
   * get the X translation portion of this transform
@@ -109,7 +109,7 @@ public:
   **/
 
   float GetXTranslation(void)                 { return m20; }
-  nscoord GetXTranslationCoord(void)          { return NS_TO_INT_ROUND(m20); }
+  nscoord GetXTranslationCoord(void)          { return NSToCoordRound(m20); }
 
  /**
   * get the Y translation portion of this transform
@@ -120,7 +120,7 @@ public:
   **/
 
   float GetYTranslation(void)               { return m21; }
-  nscoord GetYTranslationCoord(void)        { return NS_TO_INT_ROUND(m21); }
+  nscoord GetYTranslationCoord(void)        { return NSToCoordRound(m21); }
 
  /**
   * set this matrix and type from another Transform2D
diff --git a/mozilla/gfx/src/windows/nsDeviceContextWin.cpp b/mozilla/gfx/src/windows/nsDeviceContextWin.cpp
index aa3747b7de5..9e1f0b71cd2 100644
--- a/mozilla/gfx/src/windows/nsDeviceContextWin.cpp
+++ b/mozilla/gfx/src/windows/nsDeviceContextWin.cpp
@@ -24,7 +24,7 @@ nsDeviceContextWin :: nsDeviceContextWin()
 {
   HDC hdc = ::GetDC(NULL);
 
-  mTwipsToPixels = ((float)::GetDeviceCaps(hdc, LOGPIXELSX)) / NS_POINTS_TO_TWIPS_FLOAT(72.0f);
+  mTwipsToPixels = ((float)::GetDeviceCaps(hdc, LOGPIXELSX)) / (float)NSIntPointsToTwips(72); // XXX shouldn't be LOGPIXELSY ??
   mPixelsToTwips = 1.0f / mTwipsToPixels;
 
   ::ReleaseDC(NULL, hdc);
diff --git a/mozilla/gfx/src/windows/nsFontMetricsWin.cpp b/mozilla/gfx/src/windows/nsFontMetricsWin.cpp
index a5b4bb4d1f8..4a33eeb30cb 100644
--- a/mozilla/gfx/src/windows/nsFontMetricsWin.cpp
+++ b/mozilla/gfx/src/windows/nsFontMetricsWin.cpp
@@ -162,9 +162,9 @@ void nsFontMetricsWin::RealizeFont(nsIDeviceContext *aContext)
   float app2dev = aContext->GetAppUnitsToDevUnits();
   float app2twip = app2dev * aContext->GetDevUnitsToTwips();
 
-  float rounded = NS_POINTS_TO_TWIPS_FLOAT(NS_TWIPS_TO_POINTS_INT(mFont->size * app2twip)) / app2twip;
+  float rounded = ((float)NSIntPointsToTwips(NSTwipsToFloorIntPoints(nscoord(mFont->size * app2twip)))) / app2twip;
     // round font size off to floor point size to be windows compatible
-//  logFont.lfHeight = - NS_TO_INT_ROUND(rounded * app2dev);  // this is proper (windows) rounding
+//  logFont.lfHeight = - NSToIntRound(rounded * app2dev);  // this is proper (windows) rounding
   logFont.lfHeight = - LONG(rounded * app2dev);  // this floor rounding is to make ours compatible with Nav 4.0
   strncpy(logFont.lfFaceName,
           MapFamilyToFont(mFont->name),
diff --git a/mozilla/gfx/src/windows/nsRenderingContextWin.cpp b/mozilla/gfx/src/windows/nsRenderingContextWin.cpp
index c9f381d4465..b1092506f9a 100644
--- a/mozilla/gfx/src/windows/nsRenderingContextWin.cpp
+++ b/mozilla/gfx/src/windows/nsRenderingContextWin.cpp
@@ -954,8 +954,8 @@ void nsRenderingContextWin :: DrawImage(nsIImage *aImage, nscoord aX, nscoord aY
 
   nscoord width, height;
 
-  width = NS_TO_INT_ROUND(mP2T * aImage->GetWidth());
-  height = NS_TO_INT_ROUND(mP2T * aImage->GetHeight());
+  width = NSToCoordRound(mP2T * aImage->GetWidth());
+  height = NSToCoordRound(mP2T * aImage->GetHeight());
 
   this->DrawImage(aImage, aX, aY, width, height);
 }
diff --git a/mozilla/layout/base/nsCSSRendering.cpp b/mozilla/layout/base/nsCSSRendering.cpp
index 55a04c0543d..1987d833978 100644
--- a/mozilla/layout/base/nsCSSRendering.cpp
+++ b/mozilla/layout/base/nsCSSRendering.cpp
@@ -693,8 +693,8 @@ void nsCSSRendering::PaintBackground(nsIPresContext& aPresContext,
 
     // Convert image dimensions into nscoord's
     float p2t = aPresContext.GetPixelsToTwips();
-    nscoord tileWidth = nscoord(p2t * imageSize.width);
-    nscoord tileHeight = nscoord(p2t * imageSize.height);
+    nscoord tileWidth = NSIntPixelsToTwips(imageSize.width, p2t);
+    nscoord tileHeight = NSIntPixelsToTwips(imageSize.height, p2t);
 
     PRIntn repeat = aColor.mBackgroundRepeat;
     PRIntn xcount, ycount;
diff --git a/mozilla/layout/base/nsPresContext.cpp b/mozilla/layout/base/nsPresContext.cpp
index 556a9a6e367..e6cd53a78a9 100644
--- a/mozilla/layout/base/nsPresContext.cpp
+++ b/mozilla/layout/base/nsPresContext.cpp
@@ -36,12 +36,12 @@ nsPresContext::nsPresContext()
                  NS_FONT_VARIANT_NORMAL,
                  NS_FONT_WEIGHT_NORMAL,
                  0,
-                 NS_POINTS_TO_TWIPS_INT(12)),
+                 NSIntPointsToTwips(12)),
     mDefaultFixedFont("Courier", NS_FONT_STYLE_NORMAL,
                       NS_FONT_VARIANT_NORMAL,
                       NS_FONT_WEIGHT_NORMAL,
                       0,
-                      NS_POINTS_TO_TWIPS_INT(10))
+                      NSIntPointsToTwips(10))
 {
   NS_INIT_REFCNT();
   mShell = nsnull;
@@ -138,13 +138,13 @@ nsPresContext::Init(nsIDeviceContext* aDeviceContext, nsIPref* aPrefs)
       mDefaultFont.name = prefChar;
     }
     if (NS_OK == mPrefs->GetIntPref("intl.font2.win.prop_size", &prefInt)) {
-      mDefaultFont.size = NS_POINTS_TO_TWIPS_INT(prefInt);
+      mDefaultFont.size = NSIntPointsToTwips(prefInt);
     }
     if (NS_OK == mPrefs->GetCharPref("intl.font2.win.fixed_font", &(prefChar[0]), &charSize)) {
       mDefaultFixedFont.name = prefChar;
     }
     if (NS_OK == mPrefs->GetIntPref("intl.font2.win.fixed_size", &prefInt)) {
-      mDefaultFixedFont.size = NS_POINTS_TO_TWIPS_INT(prefInt);
+      mDefaultFixedFont.size = NSIntPointsToTwips(prefInt);
     }
   }
 
diff --git a/mozilla/layout/base/src/nsFrameImageLoader.cpp b/mozilla/layout/base/src/nsFrameImageLoader.cpp
index 8112888778f..bcbebcffd85 100644
--- a/mozilla/layout/base/src/nsFrameImageLoader.cpp
+++ b/mozilla/layout/base/src/nsFrameImageLoader.cpp
@@ -202,10 +202,10 @@ nsFrameImageLoader::Notify(nsIImageRequest *aImageRequest,
     // Convert the rect from pixels to twips
     p2t = mPresContext->GetPixelsToTwips();
     changeRect = (const nsRect*)aParam3;
-    damageRect.x = nscoord(p2t * changeRect->x);
-    damageRect.y = nscoord(p2t * changeRect->y);
-    damageRect.width = nscoord(p2t * changeRect->width);
-    damageRect.height = nscoord(p2t * changeRect->height);
+    damageRect.x = NSIntPixelsToTwips(changeRect->x, p2t);
+    damageRect.y = NSIntPixelsToTwips(changeRect->y, p2t);
+    damageRect.width = NSIntPixelsToTwips(changeRect->width, p2t);
+    damageRect.height = NSIntPixelsToTwips(changeRect->height, p2t);
     DamageRepairFrame(&damageRect);
     break;
 
diff --git a/mozilla/layout/base/src/nsPresContext.cpp b/mozilla/layout/base/src/nsPresContext.cpp
index 556a9a6e367..e6cd53a78a9 100644
--- a/mozilla/layout/base/src/nsPresContext.cpp
+++ b/mozilla/layout/base/src/nsPresContext.cpp
@@ -36,12 +36,12 @@ nsPresContext::nsPresContext()
                  NS_FONT_VARIANT_NORMAL,
                  NS_FONT_WEIGHT_NORMAL,
                  0,
-                 NS_POINTS_TO_TWIPS_INT(12)),
+                 NSIntPointsToTwips(12)),
     mDefaultFixedFont("Courier", NS_FONT_STYLE_NORMAL,
                       NS_FONT_VARIANT_NORMAL,
                       NS_FONT_WEIGHT_NORMAL,
                       0,
-                      NS_POINTS_TO_TWIPS_INT(10))
+                      NSIntPointsToTwips(10))
 {
   NS_INIT_REFCNT();
   mShell = nsnull;
@@ -138,13 +138,13 @@ nsPresContext::Init(nsIDeviceContext* aDeviceContext, nsIPref* aPrefs)
       mDefaultFont.name = prefChar;
     }
     if (NS_OK == mPrefs->GetIntPref("intl.font2.win.prop_size", &prefInt)) {
-      mDefaultFont.size = NS_POINTS_TO_TWIPS_INT(prefInt);
+      mDefaultFont.size = NSIntPointsToTwips(prefInt);
     }
     if (NS_OK == mPrefs->GetCharPref("intl.font2.win.fixed_font", &(prefChar[0]), &charSize)) {
       mDefaultFixedFont.name = prefChar;
     }
     if (NS_OK == mPrefs->GetIntPref("intl.font2.win.fixed_size", &prefInt)) {
-      mDefaultFixedFont.size = NS_POINTS_TO_TWIPS_INT(prefInt);
+      mDefaultFixedFont.size = NSIntPointsToTwips(prefInt);
     }
   }
 
diff --git a/mozilla/layout/base/src/nsPresShell.cpp b/mozilla/layout/base/src/nsPresShell.cpp
index f111809f3c2..93cc02ff278 100644
--- a/mozilla/layout/base/src/nsPresShell.cpp
+++ b/mozilla/layout/base/src/nsPresShell.cpp
@@ -1041,7 +1041,6 @@ PresShell::VerifyIncrementalReflow()
   // Create a new presentation shell to view the document
   rv = mDocument->CreateShell(cx, vm, ss, &sh);
   NS_ASSERTION(NS_OK == rv, "failed to create presentation shell");
-  float p2t = cx->GetPixelsToTwips();
   sh->ResizeReflow(r.width, r.height);
 
   // Now that the document has been reflowed, use its frame tree to
diff --git a/mozilla/layout/base/src/nsPrintPreviewContext.cpp b/mozilla/layout/base/src/nsPrintPreviewContext.cpp
index c50e6828314..0ed1467b0d5 100644
--- a/mozilla/layout/base/src/nsPrintPreviewContext.cpp
+++ b/mozilla/layout/base/src/nsPrintPreviewContext.cpp
@@ -55,7 +55,7 @@ nscoord PrintPreviewContext::GetPageWidth()
 #else
   // For testing purposes make the page width smaller than the visible
   // area
-  nscoord sbar = NS_TO_INT_ROUND(mDeviceContext->GetScrollBarWidth());
+  nscoord sbar = NSToCoordRound(mDeviceContext->GetScrollBarWidth());
   return mVisibleArea.width - sbar - 2*100;
 #endif
 }
diff --git a/mozilla/layout/base/src/nsStyleContext.cpp b/mozilla/layout/base/src/nsStyleContext.cpp
index cd3514441f9..a520fa357f4 100644
--- a/mozilla/layout/base/src/nsStyleContext.cpp
+++ b/mozilla/layout/base/src/nsStyleContext.cpp
@@ -245,9 +245,9 @@ void nsStyleSpacing::CalcPaddingFor(const nsIFrame* aFrame, nsMargin& aPadding)
 }
 
 static const nscoord kBorderWidths[3] = 
-  { NS_POINTS_TO_TWIPS_INT(1), 
-    NS_POINTS_TO_TWIPS_INT(3), 
-    NS_POINTS_TO_TWIPS_INT(5) };
+  { NSIntPointsToTwips(1), 
+    NSIntPointsToTwips(3), 
+    NSIntPointsToTwips(5) };
 
 void nsStyleSpacing::CalcBorderFor(const nsIFrame* aFrame, nsMargin& aBorder) const
 {
diff --git a/mozilla/layout/events/src/nsDOMEvent.cpp b/mozilla/layout/events/src/nsDOMEvent.cpp
index 97e38f75804..81bb727b7be 100644
--- a/mozilla/layout/events/src/nsDOMEvent.cpp
+++ b/mozilla/layout/events/src/nsDOMEvent.cpp
@@ -128,7 +128,7 @@ NS_METHOD nsDOMEvent::SetScreenY(PRInt32 aScreenY)
 
 NS_METHOD nsDOMEvent::GetClientX(PRInt32* aClientX)
 {
-  *aClientX = NS_TO_INT_ROUND(mEvent->point.x * mPresContext->GetTwipsToPixels());
+  *aClientX = NSTwipsToIntPixels(mEvent->point.x, mPresContext->GetTwipsToPixels());
   return NS_OK;
 }
 
@@ -139,7 +139,7 @@ NS_METHOD nsDOMEvent::SetClientX(PRInt32 aClientX)
 
 NS_METHOD nsDOMEvent::GetClientY(PRInt32* aClientY)
 {
-  *aClientY = NS_TO_INT_ROUND(mEvent->point.y * mPresContext->GetTwipsToPixels());
+  *aClientY = NSTwipsToIntPixels(mEvent->point.y, mPresContext->GetTwipsToPixels());
   return NS_OK;
 }
 
diff --git a/mozilla/layout/generic/nsImageMap.cpp b/mozilla/layout/generic/nsImageMap.cpp
index 2122aa7f02b..a568255000d 100644
--- a/mozilla/layout/generic/nsImageMap.cpp
+++ b/mozilla/layout/generic/nsImageMap.cpp
@@ -25,9 +25,6 @@
 #include "nsXIFConverter.h"
 #include "nsISizeOfHandler.h"
 
-#undef SCALE
-#define SCALE(a,b) nscoord((a) * (b))
-
 class Area {
 public:
   Area(const nsString& aBaseURL, const nsString& aHREF,
@@ -455,10 +452,10 @@ void RectArea::Draw(nsIPresContext& aCX, nsIRenderingContext& aRC)
 {
   if (mNumCoords >= 4) {
     float p2t = aCX.GetPixelsToTwips();
-    nscoord x1 = SCALE(p2t, mCoords[0]);
-    nscoord y1 = SCALE(p2t, mCoords[1]);
-    nscoord x2 = SCALE(p2t, mCoords[2]);
-    nscoord y2 = SCALE(p2t, mCoords[3]);
+    nscoord x1 = NSIntPixelsToTwips(mCoords[0], p2t);
+    nscoord y1 = NSIntPixelsToTwips(mCoords[1], p2t);
+    nscoord x2 = NSIntPixelsToTwips(mCoords[2], p2t);
+    nscoord y2 = NSIntPixelsToTwips(mCoords[3], p2t);
     if ((x1 > x2)|| (y1 > y2)) {
       return;
     }
@@ -563,11 +560,11 @@ void PolyArea::Draw(nsIPresContext& aCX, nsIRenderingContext& aRC)
 {
   if (mNumCoords >= 6) {
     float p2t = aCX.GetPixelsToTwips();
-    nscoord x0 = SCALE(p2t, mCoords[0]);
-    nscoord y0 = SCALE(p2t, mCoords[1]);
+    nscoord x0 = NSIntPixelsToTwips(mCoords[0], p2t);
+    nscoord y0 = NSIntPixelsToTwips(mCoords[1], p2t);
     for (PRInt32 i = 2; i < mNumCoords; i += 2) {
-      nscoord x1 = SCALE(p2t, mCoords[i]);
-      nscoord y1 = SCALE(p2t, mCoords[i+1]);
+      nscoord x1 = NSIntPixelsToTwips(mCoords[i], p2t);
+      nscoord y1 = NSIntPixelsToTwips(mCoords[i+1], p2t);
       aRC.DrawLine(x0, y0, x1, y1);
       x0 = x1;
       y0 = y1;
@@ -631,9 +628,9 @@ void CircleArea::Draw(nsIPresContext& aCX, nsIRenderingContext& aRC)
 {
   if (mNumCoords >= 3) {
     float p2t = aCX.GetPixelsToTwips();
-    nscoord x1 = SCALE(p2t, mCoords[0]);
-    nscoord y1 = SCALE(p2t, mCoords[1]);
-    nscoord radius = SCALE(p2t, mCoords[2]);
+    nscoord x1 = NSIntPixelsToTwips(mCoords[0], p2t);
+    nscoord y1 = NSIntPixelsToTwips(mCoords[1], p2t);
+    nscoord radius = NSIntPixelsToTwips(mCoords[2], p2t);
     if (radius < 0) {
       return;
     }
diff --git a/mozilla/layout/generic/nsObjectFrame.cpp b/mozilla/layout/generic/nsObjectFrame.cpp
index 69813cdfa07..311c9d0fcdd 100644
--- a/mozilla/layout/generic/nsObjectFrame.cpp
+++ b/mozilla/layout/generic/nsObjectFrame.cpp
@@ -163,7 +163,7 @@ nsObjectFrame::GetDesiredSize(nsIPresContext* aPresContext,
     }
     else {
       float p2t = aPresContext->GetPixelsToTwips();
-      aMetrics.width = nscoord(p2t * EMBED_DEF_DIM);
+      aMetrics.width = NSIntPixelsToTwips(EMBED_DEF_DIM, p2t);
     }
   }
   if (!haveHeight) {
@@ -172,7 +172,7 @@ nsObjectFrame::GetDesiredSize(nsIPresContext* aPresContext,
     }
     else {
       float p2t = aPresContext->GetPixelsToTwips();
-      aMetrics.height = nscoord(p2t * EMBED_DEF_DIM);
+      aMetrics.height = NSIntPixelsToTwips(EMBED_DEF_DIM, p2t);
     }
   }
   aMetrics.ascent = aMetrics.height;
@@ -293,7 +293,7 @@ nsObjectFrame::Paint(nsIPresContext& aPresContext,
   aRenderingContext.SetColor(NS_RGB(0, 0, 0));
   aRenderingContext.DrawRect(0, 0, mRect.width, mRect.height);
   float p2t = aPresContext.GetPixelsToTwips();
-  nscoord px3 = nscoord(3 * p2t);
+  nscoord px3 = NSIntPixelsToTwips(3, p2t);
   nsAutoString tmp;
   nsIAtom* atom = mContent->GetTag();
   if (nsnull != atom) {
diff --git a/mozilla/layout/generic/nsPlaceholderFrame.cpp b/mozilla/layout/generic/nsPlaceholderFrame.cpp
index a9e1dd65266..c1b62f4ee1b 100644
--- a/mozilla/layout/generic/nsPlaceholderFrame.cpp
+++ b/mozilla/layout/generic/nsPlaceholderFrame.cpp
@@ -161,10 +161,10 @@ nsPlaceholderFrame::Paint(nsIPresContext& aPresContext,
   if (nsIFrame::GetShowFrameBorders()) {
     float p2t = aPresContext.GetPixelsToTwips();
     aRenderingContext.SetColor(NS_RGB(0, 255, 255));
-    nscoord x = nscoord(-5 * p2t);
-    aRenderingContext.FillRect(x, 0, nscoord(13 * p2t), nscoord(3 * p2t));
-    nscoord y = nscoord(-10 * p2t);
-    aRenderingContext.FillRect(0, y, nscoord(3 * p2t), nscoord(10 * p2t));
+    nscoord x = NSIntPixelsToTwips(-5, p2t);
+    aRenderingContext.FillRect(x, 0, NSIntPixelsToTwips(13, p2t), NSIntPixelsToTwips(3, p2t));
+    nscoord y = NSIntPixelsToTwips(-10, p2t);
+    aRenderingContext.FillRect(0, y, NSIntPixelsToTwips(3, p2t), NSIntPixelsToTwips(10, p2t));
   }
   return NS_OK;
 }
diff --git a/mozilla/layout/html/base/src/nsBRPart.cpp b/mozilla/layout/html/base/src/nsBRPart.cpp
index e563a3df75d..69405b5c056 100644
--- a/mozilla/layout/html/base/src/nsBRPart.cpp
+++ b/mozilla/layout/html/base/src/nsBRPart.cpp
@@ -83,7 +83,7 @@ BRFrame::Paint(nsIPresContext&      aPresContext,
   if (nsIFrame::GetShowFrameBorders()) {
     float p2t = aPresContext.GetPixelsToTwips();
     aRenderingContext.SetColor(NS_RGB(0, 255, 255));
-    aRenderingContext.FillRect(0, 0, nscoord(5 * p2t), mRect.height);
+    aRenderingContext.FillRect(0, 0, NSIntPixelsToTwips(5, p2t), mRect.height);
   }
   return NS_OK;
 }
diff --git a/mozilla/layout/html/base/src/nsBodyFrame.cpp b/mozilla/layout/html/base/src/nsBodyFrame.cpp
index f6380f308b0..f7b3f0cb4e3 100644
--- a/mozilla/layout/html/base/src/nsBodyFrame.cpp
+++ b/mozilla/layout/html/base/src/nsBodyFrame.cpp
@@ -384,7 +384,7 @@ nsSize nsBodyFrame::GetColumnAvailSpace(nsIPresContext*  aPresContext,
                       aBorderPadding.right;
       if (! aPresContext->IsPaginated()) {
         nsIDeviceContext* dc = aPresContext->GetDeviceContext();
-        result.width -= NS_TO_INT_ROUND(dc->GetScrollBarWidth());
+        result.width -= NSToCoordRound(dc->GetScrollBarWidth());
         NS_RELEASE(dc);
       }
     }
diff --git a/mozilla/layout/html/base/src/nsHRPart.cpp b/mozilla/layout/html/base/src/nsHRPart.cpp
index 98801558d5e..c4e52f95051 100644
--- a/mozilla/layout/html/base/src/nsHRPart.cpp
+++ b/mozilla/layout/html/base/src/nsHRPart.cpp
@@ -113,7 +113,7 @@ HRuleFrame::Paint(nsIPresContext&      aPresContext,
   }
 
   float p2t = aPresContext.GetPixelsToTwips();
-  nscoord thickness = nscoord(p2t * ((HRulePart*)mContent)->GetThickness());
+  nscoord thickness = NSIntPixelsToTwips(((HRulePart*)mContent)->GetThickness(), p2t);
 
   // Get style data
   const nsStyleSpacing* spacing = (const nsStyleSpacing*)
@@ -188,8 +188,8 @@ HRuleFrame::Paint(nsIPresContext&      aPresContext,
   if (!noShadeAttribute && ((printing && bevel) || !printing)) {
     // Lines render inclusively on the both the starting and ending
     // coordinate, so reduce the end coordinates by one pixel.
-    nscoord x1 = nscoord(x0 + width - p2t);
-    nscoord y1 = nscoord(y0 + height - p2t);
+    nscoord x1 = nscoord(x0 + width - NSIntPixelsToTwips(1, p2t));
+    nscoord y1 = nscoord(y0 + height - NSIntPixelsToTwips(1, p2t));
 
     // Draw bottom and right lines
     aRenderingContext.SetColor (colors[1]);
@@ -205,7 +205,7 @@ HRuleFrame::Paint(nsIPresContext&      aPresContext,
     // draw half-circles on the end points.
     aRenderingContext.SetColor (colors[0]);
     nscoord diameter = height;
-    if ((diameter > width) || (diameter < nscoord(p2t * 3))) {
+    if ((diameter > width) || (diameter < NSIntPixelsToTwips(3, p2t))) {
       // The half-circles on the ends of the rule aren't going to
       // look right so don't bother drawing them.
       aRenderingContext.FillRect(x0, y0, width, height);
@@ -238,7 +238,7 @@ HRuleFrame::Reflow(nsIPresContext&      aPresContext,
   // HR's do not impact the max-element-size, otherwise tables behave
   // badly. This makes sense they are springy.
   if (nsnull != aDesiredSize.maxElementSize) {
-    nscoord onePixel = nscoord(aPresContext.GetPixelsToTwips());
+    nscoord onePixel = NSIntPixelsToTwips(1, aPresContext.GetPixelsToTwips());
     aDesiredSize.maxElementSize->width = onePixel;
     aDesiredSize.maxElementSize->height = onePixel;
   }
@@ -278,11 +278,11 @@ HRuleFrame::GetDesiredSize(nsIPresContext* aPresContext,
 
   // Get the thickness of the rule (this is not css's height property)
   float p2t = aPresContext->GetPixelsToTwips();
-  nscoord thickness = nscoord(p2t * ((HRulePart*)mContent)->GetThickness());
+  nscoord thickness = NSIntPixelsToTwips(((HRulePart*)mContent)->GetThickness(), p2t);
 
   // Compute height of "line" that hrule will layout within. Use the
   // default font to do this.
-  lineHeight = thickness + nscoord(p2t * 2);
+  lineHeight = thickness + NSIntPixelsToTwips(2, p2t);
   const nsFont& defaultFont = aPresContext->GetDefaultFont();
   nsIFontMetrics* fm = aPresContext->GetMetricsFor(defaultFont);
   nscoord defaultLineHeight = fm->GetHeight();
@@ -414,7 +414,7 @@ HRulePart::MapAttributesInto(nsIStyleContext* aContext,
       aContext->GetMutableStyleData(eStyleStruct_Position);
     GetAttribute(nsHTMLAtoms::width, value);
     if (value.GetUnit() == eHTMLUnit_Pixel) {
-      nscoord twips = nscoord(p2t * value.GetPixelValue());
+      nscoord twips = NSIntPixelsToTwips(value.GetPixelValue(), p2t);
       pos->mWidth.SetCoordValue(twips);
     }
     else if (value.GetUnit() == eHTMLUnit_Percent) {
diff --git a/mozilla/layout/html/base/src/nsHTMLBullet.cpp b/mozilla/layout/html/base/src/nsHTMLBullet.cpp
index 5e28cda6d36..e146a389b23 100644
--- a/mozilla/layout/html/base/src/nsHTMLBullet.cpp
+++ b/mozilla/layout/html/base/src/nsHTMLBullet.cpp
@@ -557,12 +557,12 @@ BulletFrame::GetDesiredSize(nsIPresContext*  aCX,
   case NS_STYLE_LIST_STYLE_BASIC:
   case NS_STYLE_LIST_STYLE_SQUARE:
     t2p = aCX->GetTwipsToPixels();
-    bulletSize = nscoord(t2p * .8 * (fm->GetMaxAscent() / 2));
+    bulletSize = NSTwipsToIntPixels((nscoord)NSToIntRound(0.8f * (float(fm->GetMaxAscent()) / 2.0f)), t2p);
     if (bulletSize < 1) {
       bulletSize = MIN_BULLET_SIZE;
     }
     p2t = aCX->GetPixelsToTwips();
-    bulletSize = nscoord(p2t * bulletSize);
+    bulletSize = NSIntPixelsToTwips(bulletSize, p2t);
     mPadding.bottom = (fm->GetMaxAscent() / 8);
     if (NS_STYLE_LIST_STYLE_POSITION_INSIDE == myList->mListStylePosition) {
       mPadding.right = bulletSize / 2;
diff --git a/mozilla/layout/html/base/src/nsHTMLContainer.cpp b/mozilla/layout/html/base/src/nsHTMLContainer.cpp
index a5f5421941a..54d3af3e37c 100644
--- a/mozilla/layout/html/base/src/nsHTMLContainer.cpp
+++ b/mozilla/layout/html/base/src/nsHTMLContainer.cpp
@@ -616,13 +616,13 @@ void nsHTMLContainer::MapAttributesInto(nsIStyleContext* aContext,
       GetAttribute(nsHTMLAtoms::pointSize, value);
       if (value.GetUnit() == eHTMLUnit_Integer) {
         // XXX should probably sanitize value
-        font->mFont.size = parentFont->mFont.size + NS_POINTS_TO_TWIPS_INT(value.GetIntValue());
-        font->mFixedFont.size = parentFont->mFixedFont.size + NS_POINTS_TO_TWIPS_INT(value.GetIntValue());
+        font->mFont.size = parentFont->mFont.size + NSIntPointsToTwips(value.GetIntValue());
+        font->mFixedFont.size = parentFont->mFixedFont.size + NSIntPointsToTwips(value.GetIntValue());
         font->mFlags |= NS_STYLE_FONT_SIZE_EXPLICIT;
       }
       else if (value.GetUnit() == eHTMLUnit_Enumerated) {
-        font->mFont.size = NS_POINTS_TO_TWIPS_INT(value.GetIntValue());
-        font->mFixedFont.size = NS_POINTS_TO_TWIPS_INT(value.GetIntValue());
+        font->mFont.size = NSIntPointsToTwips(value.GetIntValue());
+        font->mFixedFont.size = NSIntPointsToTwips(value.GetIntValue());
         font->mFlags |= NS_STYLE_FONT_SIZE_EXPLICIT;
       }
       else {
diff --git a/mozilla/layout/html/base/src/nsHTMLImage.cpp b/mozilla/layout/html/base/src/nsHTMLImage.cpp
index 18180f6bab2..5fe1437094e 100644
--- a/mozilla/layout/html/base/src/nsHTMLImage.cpp
+++ b/mozilla/layout/html/base/src/nsHTMLImage.cpp
@@ -316,14 +316,14 @@ nsHTMLImageLoader::GetDesiredSize(nsIPresContext* aPresContext,
             // from width.
             aDesiredSize.width = styleSize.width;
             aDesiredSize.height =
-              nscoord(styleSize.width * imageHeight / imageWidth);
+              (nscoord)NSToIntRound(styleSize.width * imageHeight / imageWidth);
           }
           else {
             // We have a height and an auto width. Compute width from
             // height.
             aDesiredSize.height = styleSize.height;
             aDesiredSize.width =
-              nscoord(styleSize.height * imageWidth / imageHeight);
+              (nscoord)NSToIntRound(styleSize.height * imageWidth / imageHeight);
           }
         }
         else {
@@ -346,8 +346,8 @@ nsHTMLImageLoader::GetDesiredSize(nsIPresContext* aPresContext,
       float p2t = aPresContext->GetPixelsToTwips();
       nsSize imageSize;
       mImageLoader->GetSize(imageSize);
-      aDesiredSize.width = nscoord(imageSize.width * p2t);
-      aDesiredSize.height = nscoord(imageSize.height * p2t);
+      aDesiredSize.width = NSIntPixelsToTwips(imageSize.width, p2t);
+      aDesiredSize.height = NSIntPixelsToTwips(imageSize.height, p2t);
     }
   }
 }
@@ -595,14 +595,14 @@ ImageFrame::Paint(nsIPresContext& aPresContext,
         nsRect  inner;
         GetInnerArea(&aPresContext, inner);
 
-        nscoord p2t = (nscoord)aPresContext.GetPixelsToTwips();
-        nsRecessedBorder recessedBorder(p2t);
+        float p2t = aPresContext.GetPixelsToTwips();
+        nsRecessedBorder recessedBorder(NSIntPixelsToTwips(1, p2t));
         nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, this, inner,
                                     inner, recessedBorder, 0);
-        inner.Deflate(p2t, p2t);
+        inner.Deflate(NSIntPixelsToTwips(1, p2t), NSIntPixelsToTwips(1, p2t));
 
         // Leave a 8 pixel left/right padding, and a 5 pixel top/bottom padding
-        inner.Deflate(8 * p2t, 5 * p2t);
+        inner.Deflate(NSIntPixelsToTwips(8, p2t), NSIntPixelsToTwips(5, p2t));
 
         // If there's room, then display the alt-text
         if (!inner.IsEmpty()) {
@@ -618,8 +618,8 @@ ImageFrame::Paint(nsIPresContext& aPresContext,
     GetInnerArea(&aPresContext, inner);
     if (mImageLoader.GetLoadImageFailed()) {
       float p2t = aPresContext.GetPixelsToTwips();
-      inner.width = nscoord(p2t * image->GetWidth());
-      inner.height = nscoord(p2t * image->GetHeight());
+      inner.width = NSIntPixelsToTwips(image->GetWidth(), p2t);
+      inner.height = NSIntPixelsToTwips(image->GetHeight(), p2t);
     }
     aRenderingContext.DrawImage(image, inner);
 
@@ -745,8 +745,8 @@ ImageFrame::HandleEvent(nsIPresContext& aPresContext,
         // the image's borders.
         nsRect inner;
         GetInnerArea(&aPresContext, inner);
-        nscoord x = nscoord(t2p * (aEvent->point.x - inner.x));
-        nscoord y = nscoord(t2p * (aEvent->point.y - inner.y));
+        PRInt32 x = NSTwipsToIntPixels((aEvent->point.x - inner.x), t2p);
+        PRInt32 y = NSTwipsToIntPixels((aEvent->point.y - inner.y), t2p);
         nsresult r = map->IsInside(x, y, docURL, absURL, target, altText,
                                    &suppress);
         NS_IF_RELEASE(docURL);
@@ -771,8 +771,8 @@ ImageFrame::HandleEvent(nsIPresContext& aPresContext,
 
         // Note: We don't subtract out the border/padding here to remain
         // compatible with navigator. [ick]
-        nscoord x = nscoord(t2p * aEvent->point.x);
-        nscoord y = nscoord(t2p * aEvent->point.y);
+        PRInt32 x = NSTwipsToIntPixels(aEvent->point.x, t2p);
+        PRInt32 y = NSTwipsToIntPixels(aEvent->point.y, t2p);
         char cbuf[50];
         PR_snprintf(cbuf, sizeof(cbuf), "?%d,%d", x, y);
         absURL.Append(cbuf);
@@ -819,8 +819,8 @@ ImageFrame::GetCursorAndContentAt(nsIPresContext& aPresContext,
     GetInnerArea(&aPresContext, inner);
     aCursor = NS_STYLE_CURSOR_DEFAULT;
     float t2p = aPresContext.GetTwipsToPixels();
-    nscoord x = nscoord(t2p * (aPoint.x - inner.x));
-    nscoord y = nscoord(t2p * (aPoint.y - inner.y));
+    PRInt32 x = NSTwipsToIntPixels((aPoint.x - inner.x), t2p);
+    PRInt32 y = NSTwipsToIntPixels((aPoint.y - inner.y), t2p);
     if (NS_OK == map->IsInside(x, y)) {
       aCursor = NS_STYLE_CURSOR_HAND;
     }
@@ -1023,7 +1023,7 @@ nsHTMLImage::MapAttributesInto(nsIStyleContext* aContext,
       nsStyleSpacing* spacing = (nsStyleSpacing*)
         aContext->GetMutableStyleData(eStyleStruct_Spacing);
       float p2t = aPresContext->GetPixelsToTwips();
-      nsStyleCoord three(nscoord(p2t*3));
+      nsStyleCoord three(NSIntPixelsToTwips(3, p2t));
       switch (align) {
       case NS_STYLE_TEXT_ALIGN_LEFT:
         display->mFloats = NS_STYLE_FLOAT_LEFT;
diff --git a/mozilla/layout/html/base/src/nsHTMLTagContent.cpp b/mozilla/layout/html/base/src/nsHTMLTagContent.cpp
index 05c66f71b10..1e0e80fcdbf 100644
--- a/mozilla/layout/html/base/src/nsHTMLTagContent.cpp
+++ b/mozilla/layout/html/base/src/nsHTMLTagContent.cpp
@@ -1309,7 +1309,7 @@ nsHTMLTagContent::MapImagePropertiesInto(nsIStyleContext* aContext,
     // width: value
     GetAttribute(nsHTMLAtoms::width, value);
     if (value.GetUnit() == eHTMLUnit_Pixel) {
-      nscoord twips = nscoord(p2t * value.GetPixelValue());
+      nscoord twips = NSIntPixelsToTwips(value.GetPixelValue(), p2t);
       pos->mWidth.SetCoordValue(twips);
     }
     else if (value.GetUnit() == eHTMLUnit_Percent) {
@@ -1319,7 +1319,7 @@ nsHTMLTagContent::MapImagePropertiesInto(nsIStyleContext* aContext,
     // height: value
     GetAttribute(nsHTMLAtoms::height, value);
     if (value.GetUnit() == eHTMLUnit_Pixel) {
-      nscoord twips = nscoord(p2t * value.GetPixelValue());
+      nscoord twips = NSIntPixelsToTwips(value.GetPixelValue(), p2t);
       pos->mHeight.SetCoordValue(twips);
     }
     else if (value.GetUnit() == eHTMLUnit_Percent) {
@@ -1329,7 +1329,7 @@ nsHTMLTagContent::MapImagePropertiesInto(nsIStyleContext* aContext,
     // hspace: value
     GetAttribute(nsHTMLAtoms::hspace, value);
     if (value.GetUnit() == eHTMLUnit_Pixel) {
-      nscoord twips = nscoord(p2t * value.GetPixelValue());
+      nscoord twips = NSIntPixelsToTwips(value.GetPixelValue(), p2t);
       spacing->mMargin.SetRight(nsStyleCoord(twips));
     }
     else if (value.GetUnit() == eHTMLUnit_Percent) {
@@ -1340,7 +1340,7 @@ nsHTMLTagContent::MapImagePropertiesInto(nsIStyleContext* aContext,
     // vspace: value
     GetAttribute(nsHTMLAtoms::vspace, value);
     if (value.GetUnit() == eHTMLUnit_Pixel) {
-      nscoord twips = nscoord(p2t * value.GetPixelValue());
+      nscoord twips = NSIntPixelsToTwips(value.GetPixelValue(), p2t);
       spacing->mMargin.SetBottom(nsStyleCoord(twips));
     }
     else if (value.GetUnit() == eHTMLUnit_Percent) {
@@ -1370,7 +1370,7 @@ nsHTMLTagContent::MapImageBorderInto(nsIStyleContext* aContext,
     }
 
     float p2t = aPresContext->GetPixelsToTwips();
-    nscoord twips = nscoord(p2t * value.GetPixelValue());
+    nscoord twips = NSIntPixelsToTwips(value.GetPixelValue(), p2t);
 
     // Fixup border-padding sums: subtract out the old size and then
     // add in the new size.
diff --git a/mozilla/layout/html/base/src/nsImageMap.cpp b/mozilla/layout/html/base/src/nsImageMap.cpp
index 2122aa7f02b..a568255000d 100644
--- a/mozilla/layout/html/base/src/nsImageMap.cpp
+++ b/mozilla/layout/html/base/src/nsImageMap.cpp
@@ -25,9 +25,6 @@
 #include "nsXIFConverter.h"
 #include "nsISizeOfHandler.h"
 
-#undef SCALE
-#define SCALE(a,b) nscoord((a) * (b))
-
 class Area {
 public:
   Area(const nsString& aBaseURL, const nsString& aHREF,
@@ -455,10 +452,10 @@ void RectArea::Draw(nsIPresContext& aCX, nsIRenderingContext& aRC)
 {
   if (mNumCoords >= 4) {
     float p2t = aCX.GetPixelsToTwips();
-    nscoord x1 = SCALE(p2t, mCoords[0]);
-    nscoord y1 = SCALE(p2t, mCoords[1]);
-    nscoord x2 = SCALE(p2t, mCoords[2]);
-    nscoord y2 = SCALE(p2t, mCoords[3]);
+    nscoord x1 = NSIntPixelsToTwips(mCoords[0], p2t);
+    nscoord y1 = NSIntPixelsToTwips(mCoords[1], p2t);
+    nscoord x2 = NSIntPixelsToTwips(mCoords[2], p2t);
+    nscoord y2 = NSIntPixelsToTwips(mCoords[3], p2t);
     if ((x1 > x2)|| (y1 > y2)) {
       return;
     }
@@ -563,11 +560,11 @@ void PolyArea::Draw(nsIPresContext& aCX, nsIRenderingContext& aRC)
 {
   if (mNumCoords >= 6) {
     float p2t = aCX.GetPixelsToTwips();
-    nscoord x0 = SCALE(p2t, mCoords[0]);
-    nscoord y0 = SCALE(p2t, mCoords[1]);
+    nscoord x0 = NSIntPixelsToTwips(mCoords[0], p2t);
+    nscoord y0 = NSIntPixelsToTwips(mCoords[1], p2t);
     for (PRInt32 i = 2; i < mNumCoords; i += 2) {
-      nscoord x1 = SCALE(p2t, mCoords[i]);
-      nscoord y1 = SCALE(p2t, mCoords[i+1]);
+      nscoord x1 = NSIntPixelsToTwips(mCoords[i], p2t);
+      nscoord y1 = NSIntPixelsToTwips(mCoords[i+1], p2t);
       aRC.DrawLine(x0, y0, x1, y1);
       x0 = x1;
       y0 = y1;
@@ -631,9 +628,9 @@ void CircleArea::Draw(nsIPresContext& aCX, nsIRenderingContext& aRC)
 {
   if (mNumCoords >= 3) {
     float p2t = aCX.GetPixelsToTwips();
-    nscoord x1 = SCALE(p2t, mCoords[0]);
-    nscoord y1 = SCALE(p2t, mCoords[1]);
-    nscoord radius = SCALE(p2t, mCoords[2]);
+    nscoord x1 = NSIntPixelsToTwips(mCoords[0], p2t);
+    nscoord y1 = NSIntPixelsToTwips(mCoords[1], p2t);
+    nscoord radius = NSIntPixelsToTwips(mCoords[2], p2t);
     if (radius < 0) {
       return;
     }
diff --git a/mozilla/layout/html/base/src/nsObjectFrame.cpp b/mozilla/layout/html/base/src/nsObjectFrame.cpp
index 69813cdfa07..311c9d0fcdd 100644
--- a/mozilla/layout/html/base/src/nsObjectFrame.cpp
+++ b/mozilla/layout/html/base/src/nsObjectFrame.cpp
@@ -163,7 +163,7 @@ nsObjectFrame::GetDesiredSize(nsIPresContext* aPresContext,
     }
     else {
       float p2t = aPresContext->GetPixelsToTwips();
-      aMetrics.width = nscoord(p2t * EMBED_DEF_DIM);
+      aMetrics.width = NSIntPixelsToTwips(EMBED_DEF_DIM, p2t);
     }
   }
   if (!haveHeight) {
@@ -172,7 +172,7 @@ nsObjectFrame::GetDesiredSize(nsIPresContext* aPresContext,
     }
     else {
       float p2t = aPresContext->GetPixelsToTwips();
-      aMetrics.height = nscoord(p2t * EMBED_DEF_DIM);
+      aMetrics.height = NSIntPixelsToTwips(EMBED_DEF_DIM, p2t);
     }
   }
   aMetrics.ascent = aMetrics.height;
@@ -293,7 +293,7 @@ nsObjectFrame::Paint(nsIPresContext& aPresContext,
   aRenderingContext.SetColor(NS_RGB(0, 0, 0));
   aRenderingContext.DrawRect(0, 0, mRect.width, mRect.height);
   float p2t = aPresContext.GetPixelsToTwips();
-  nscoord px3 = nscoord(3 * p2t);
+  nscoord px3 = NSIntPixelsToTwips(3, p2t);
   nsAutoString tmp;
   nsIAtom* atom = mContent->GetTag();
   if (nsnull != atom) {
diff --git a/mozilla/layout/html/base/src/nsPlaceholderFrame.cpp b/mozilla/layout/html/base/src/nsPlaceholderFrame.cpp
index a9e1dd65266..c1b62f4ee1b 100644
--- a/mozilla/layout/html/base/src/nsPlaceholderFrame.cpp
+++ b/mozilla/layout/html/base/src/nsPlaceholderFrame.cpp
@@ -161,10 +161,10 @@ nsPlaceholderFrame::Paint(nsIPresContext& aPresContext,
   if (nsIFrame::GetShowFrameBorders()) {
     float p2t = aPresContext.GetPixelsToTwips();
     aRenderingContext.SetColor(NS_RGB(0, 255, 255));
-    nscoord x = nscoord(-5 * p2t);
-    aRenderingContext.FillRect(x, 0, nscoord(13 * p2t), nscoord(3 * p2t));
-    nscoord y = nscoord(-10 * p2t);
-    aRenderingContext.FillRect(0, y, nscoord(3 * p2t), nscoord(10 * p2t));
+    nscoord x = NSIntPixelsToTwips(-5, p2t);
+    aRenderingContext.FillRect(x, 0, NSIntPixelsToTwips(13, p2t), NSIntPixelsToTwips(3, p2t));
+    nscoord y = NSIntPixelsToTwips(-10, p2t);
+    aRenderingContext.FillRect(0, y, NSIntPixelsToTwips(3, p2t), NSIntPixelsToTwips(10, p2t));
   }
   return NS_OK;
 }
diff --git a/mozilla/layout/html/base/src/nsRootPart.cpp b/mozilla/layout/html/base/src/nsRootPart.cpp
index 0f32dae158b..d8329378084 100644
--- a/mozilla/layout/html/base/src/nsRootPart.cpp
+++ b/mozilla/layout/html/base/src/nsRootPart.cpp
@@ -356,7 +356,7 @@ NS_METHOD RootContentFrame::Reflow(nsIPresContext&      aPresContext,
                                  aPresContext.GetPageHeight());
         nsIDeviceContext *dx = aPresContext.GetDeviceContext();
         PRInt32 extra = aReflowState.maxSize.width - PAGE_SPACING_TWIPS*2 -
-          pageSize.width - NS_TO_INT_ROUND(dx->GetScrollBarWidth());
+          pageSize.width - NSToCoordRound(dx->GetScrollBarWidth());
         NS_RELEASE(dx);
 
         // Note: nscoord is an unsigned type so don't combine these
diff --git a/mozilla/layout/html/base/src/nsScrollFrame.cpp b/mozilla/layout/html/base/src/nsScrollFrame.cpp
index 5656e238817..62a5c82e12d 100644
--- a/mozilla/layout/html/base/src/nsScrollFrame.cpp
+++ b/mozilla/layout/html/base/src/nsScrollFrame.cpp
@@ -167,8 +167,8 @@ nsScrollBodyFrame::Reflow(nsIPresContext&      aPresContext,
           // Place and size the page. If the page is narrower than our
           // max width then center it horizontally
           nsIDeviceContext *dx = aPresContext.GetDeviceContext();
-          PRInt32 extra = aReflowState.maxSize.width - kidSize.width -
-                          NS_TO_INT_ROUND(dx->GetScrollBarWidth());
+          nscoord extra = aReflowState.maxSize.width - kidSize.width -
+                          NSToCoordRound(dx->GetScrollBarWidth());
           NS_RELEASE(dx);
           nscoord         x = extra > 0 ? extra / 2 : 0;
 
@@ -380,7 +380,7 @@ nsScrollInnerFrame::Reflow(nsIPresContext&      aPresContext,
   nsSize        maxSize;
   nsIDeviceContext* dc = aPresContext.GetDeviceContext();
   maxSize.width = aReflowState.maxSize.width -
-    NS_TO_INT_ROUND(dc->GetScrollBarWidth());
+    NSToCoordRound(dc->GetScrollBarWidth());
   NS_RELEASE(dc);
   maxSize.height = NS_UNCONSTRAINEDSIZE;
   
diff --git a/mozilla/layout/html/base/src/nsSpacerPart.cpp b/mozilla/layout/html/base/src/nsSpacerPart.cpp
index e7f5cb8ef54..11fbe57211a 100644
--- a/mozilla/layout/html/base/src/nsSpacerPart.cpp
+++ b/mozilla/layout/html/base/src/nsSpacerPart.cpp
@@ -141,21 +141,21 @@ SpacerFrame::InlineReflow(nsCSSLineLayout&     aLineLayout,
   switch (type) {
   case TYPE_WORD:
     if (0 != width) {
-      aMetrics.width = nscoord(width * p2t);
+      aMetrics.width = NSIntPixelsToTwips(width, p2t);
     }
     break;
 
   case TYPE_LINE:
     if (0 != width) {
       rv = NS_INLINE_LINE_BREAK_AFTER(0);
-      aMetrics.height = nscoord(width * p2t);
+      aMetrics.height = NSIntPixelsToTwips(width, p2t);
       aMetrics.ascent = aMetrics.height;
     }
     break;
 
   case TYPE_IMAGE:
-    aMetrics.width = nscoord(width * p2t);
-    aMetrics.height = nscoord(height * p2t);
+    aMetrics.width = NSIntPixelsToTwips(width, p2t);
+    aMetrics.height = NSIntPixelsToTwips(height, p2t);
     aMetrics.ascent = aMetrics.height;
     break;
   }
diff --git a/mozilla/layout/html/base/src/nsTextContent.cpp b/mozilla/layout/html/base/src/nsTextContent.cpp
index 001342aee77..5ab77d64c32 100644
--- a/mozilla/layout/html/base/src/nsTextContent.cpp
+++ b/mozilla/layout/html/base/src/nsTextContent.cpp
@@ -514,7 +514,7 @@ NS_METHOD TextFrame::Paint(nsIPresContext& aPresContext,
 
 #if XXX
     if (font->mThreeD) {
-      nscoord onePixel = nscoord(1.0f * aPresContext.GetPixelsToTwips());
+      nscoord onePixel = NSIntPixelsToTwips(1, aPresContext.GetPixelsToTwips());
       aRenderingContext.SetColor(color->mBackgroundColor);
       PaintRegularText(aPresContext, aRenderingContext, aDirtyRect, onePixel, onePixel);
     }
diff --git a/mozilla/layout/html/content/src/nsObjectContent.cpp b/mozilla/layout/html/content/src/nsObjectContent.cpp
index 2c13647a2dc..ca9fd1bf73b 100644
--- a/mozilla/layout/html/content/src/nsObjectContent.cpp
+++ b/mozilla/layout/html/content/src/nsObjectContent.cpp
@@ -101,7 +101,7 @@ nsObjectContent::MapAttributesInto(nsIStyleContext* aContext,
       nsStyleSpacing* spacing = (nsStyleSpacing*)
         aContext->GetMutableStyleData(eStyleStruct_Spacing);
       float p2t = aPresContext->GetPixelsToTwips();
-      nsStyleCoord three(nscoord(p2t*3));
+      nsStyleCoord three(NSIntPixelsToTwips(3, p2t));
       switch (align) {
       case NS_STYLE_TEXT_ALIGN_LEFT:
         display->mFloats = NS_STYLE_FLOAT_LEFT;
diff --git a/mozilla/layout/html/document/src/nsHTMLContentSink.cpp b/mozilla/layout/html/document/src/nsHTMLContentSink.cpp
index cf1b6c98d79..d7d83c3e9f2 100644
--- a/mozilla/layout/html/document/src/nsHTMLContentSink.cpp
+++ b/mozilla/layout/html/document/src/nsHTMLContentSink.cpp
@@ -1158,7 +1158,7 @@ HTMLContentSink::ScrollToRef()
 #if 0
 nsIPresContext* cx = shell->GetPresContext();
 float t2p = cx->GetTwipsToPixels();
-printf("x=%d y=%d\n", nscoord(x * t2p), nscoord(y * t2p));
+printf("x=%d y=%d\n", NSTwipsToIntPixels(x, t2p), NSTwipsToIntPixels(y, t2p));
 NS_RELEASE(cx);
 #endif
                 sview->SetScrollPreference(mOriginalScrollPreference);
diff --git a/mozilla/layout/html/document/src/nsHTMLFrame.cpp b/mozilla/layout/html/document/src/nsHTMLFrame.cpp
index b462b7b65c3..384a3757896 100644
--- a/mozilla/layout/html/document/src/nsHTMLFrame.cpp
+++ b/mozilla/layout/html/document/src/nsHTMLFrame.cpp
@@ -257,10 +257,10 @@ nsHTMLFrameOuterFrame::GetDesiredSize(nsIPresContext* aPresContext,
 
   // XXX this needs to be changed from (200,200) to a better default for inline frames
   if (0 == (ss & NS_SIZE_HAS_WIDTH)) {
-    size.width = (nscoord)(200.0 * p2t + 0.5);
+    size.width = NSIntPixelsToTwips(200, p2t);
   }
   if (0 == (ss & NS_SIZE_HAS_HEIGHT)) {
-    size.height = (nscoord)(200 * p2t + 0.5);
+    size.height = NSIntPixelsToTwips(200, p2t);
   }
 
   aDesiredSize.width  = size.width;
@@ -550,8 +550,8 @@ nsHTMLFrameInnerFrame::CreateWebShell(nsIPresContext& aPresContext,
 
   nsIWidget* widget = view->GetWidget();
   NS_RELEASE(view);
-  nsRect webBounds(0, 0, NS_TO_INT_ROUND(aSize.width * t2p), 
-                   NS_TO_INT_ROUND(aSize.height * t2p));
+  nsRect webBounds(0, 0, NSToCoordRound(aSize.width * t2p), 
+                   NSToCoordRound(aSize.height * t2p));
 
   mWebShell->Init(widget->GetNativeData(NS_NATIVE_WIDGET), webBounds, 
                    content->GetScrolling());
@@ -613,8 +613,8 @@ nsHTMLFrameInnerFrame::Reflow(nsIPresContext&      aPresContext,
   float t2p = aPresContext.GetTwipsToPixels();
   nsRect subBounds;
   mWebShell->GetBounds(subBounds);
-  subBounds.width  = NS_TO_INT_ROUND(aDesiredSize.width * t2p);
-  subBounds.height = NS_TO_INT_ROUND(aDesiredSize.height * t2p);
+  subBounds.width  = NSToCoordRound(aDesiredSize.width * t2p);
+  subBounds.height = NSToCoordRound(aDesiredSize.height * t2p);
   mWebShell->SetBounds(subBounds);
 
   aStatus = NS_FRAME_COMPLETE;
diff --git a/mozilla/layout/html/document/src/nsHTMLFrameset.cpp b/mozilla/layout/html/document/src/nsHTMLFrameset.cpp
index e4e18ad138c..a90ecd77d5e 100644
--- a/mozilla/layout/html/document/src/nsHTMLFrameset.cpp
+++ b/mozilla/layout/html/document/src/nsHTMLFrameset.cpp
@@ -163,7 +163,7 @@ void nsHTMLFramesetFrame::CalculateRowCol(nsIPresContext* aPresContext, nscoord
         // Now that we know the size we are laying out in, turn fixed
         // pixel dimensions into percents.
         // XXX maybe use UnitConverter for proper rounding? MMP
-        aValues[i] = (nscoord) NS_TO_INT_ROUND(100 * p2t * aSpecs[i].mValue / aSize);
+        aValues[i] = NSToCoordRound(100 * p2t * aSpecs[i].mValue / aSize);
         if (aValues[i] < 1) aValues[i] = 1;
         pixel += aValues[i];
         break;
@@ -288,7 +288,7 @@ void nsHTMLFramesetFrame::CalculateRowCol(nsIPresContext* aPresContext, nscoord
 PRInt32 nsHTMLFramesetFrame::GetBorderWidth(nsIPresContext* aPresContext) 
 {
   float p2t = aPresContext->GetPixelsToTwips();
-  return NS_TO_INT_ROUND(p2t * 6);
+  return NSIntPixelsToTwips(6, p2t);
 }
 
 PRIntn
@@ -859,10 +859,10 @@ nsHTMLFramesetBorderFrame::Paint(nsIPresContext&      aPresContext,
     aRenderingContext.SetColor (color);
     aRenderingContext.DrawLine (x0, y0, x1, y1);
     if (mVertical) {
-      x0 += nscoord(p2t + 0.5);
+      x0 += NSIntPixelsToTwips(1, p2t);
       x1 =  x0;
     } else {
-      y0 += nscoord(p2t + 0.5);
+      y0 += NSIntPixelsToTwips(1, p2t);
       y1 =  y0;
     }
   }
@@ -894,8 +894,8 @@ NS_METHOD nsHTMLFramesetBorderFrame::HandleEvent(nsIPresContext& aPresContext,
           aEventStatus = nsEventStatus_eConsumeNoDefault;
         }
 	      if (eMouseDown == mLastMouseState) {
-          //((nsInput*)mContent)->SetClickPoint(NS_TO_INT_ROUND(conv * aEvent->point.x),
-          //                                    NS_TO_INT_ROUND(conv * aEvent->point.y));   
+          //((nsInput*)mContent)->SetClickPoint(NSToCoordRound(conv * aEvent->point.x),
+          //                                    NSToCoordRound(conv * aEvent->point.y));   
  		      //MouseClicked(&aPresContext);
 	        mLastMouseState = eMouseDrag;
 	      }
@@ -904,8 +904,8 @@ NS_METHOD nsHTMLFramesetBorderFrame::HandleEvent(nsIPresContext& aPresContext,
 	    break;
     case NS_MOUSE_LEFT_BUTTON_UP:
 	    if (eMouseDrag == mLastMouseState) {
-        //((nsInput*)mContent)->SetClickPoint(NS_TO_INT_ROUND(conv * aEvent->point.x),
-        //                                    NS_TO_INT_ROUND(conv * aEvent->point.y));   
+        //((nsInput*)mContent)->SetClickPoint(NSToCoordRound(conv * aEvent->point.x),
+        //                                    NSToCoordRound(conv * aEvent->point.y));   
  		    //MouseClicked(&aPresContext);
 	    } 
 	    mLastMouseState = eMouseUp;
diff --git a/mozilla/layout/html/forms/src/nsInputButton.cpp b/mozilla/layout/html/forms/src/nsInputButton.cpp
index 2f597ec07c2..652594a23ac 100644
--- a/mozilla/layout/html/forms/src/nsInputButton.cpp
+++ b/mozilla/layout/html/forms/src/nsInputButton.cpp
@@ -124,8 +124,8 @@ public:
   nsButtonType GetButtonType() const;
   nsButtonTagType GetButtonTagType() const;
 
-  virtual PRInt32 GetVerticalBorderWidth(float aPixToTwip) const;
-  virtual PRInt32 GetHorizontalBorderWidth(float aPixToTwip) const;
+  virtual nscoord GetVerticalBorderWidth(float aPixToTwip) const;
+  virtual nscoord GetHorizontalBorderWidth(float aPixToTwip) const;
   virtual nscoord GetVerticalInsidePadding(float aPixToTwip,
                                            nscoord aInnerHeight) const;
   virtual nscoord GetHorizontalInsidePadding(float aPixToTwip, 
@@ -360,12 +360,12 @@ nsInputButtonFrame::GetButtonTagType() const
   return button->GetButtonTagType();
 }
 
-PRInt32 nsInputButtonFrame::GetVerticalBorderWidth(float aPixToTwip) const
+nscoord nsInputButtonFrame::GetVerticalBorderWidth(float aPixToTwip) const
 {
-   return (int)(4 * aPixToTwip + 0.5);
+   return NSIntPixelsToTwips(4, aPixToTwip);
 }
 
-PRInt32 nsInputButtonFrame::GetHorizontalBorderWidth(float aPixToTwip) const
+nscoord nsInputButtonFrame::GetHorizontalBorderWidth(float aPixToTwip) const
 {
   return GetVerticalBorderWidth(aPixToTwip);
 }
@@ -373,12 +373,12 @@ PRInt32 nsInputButtonFrame::GetHorizontalBorderWidth(float aPixToTwip) const
 nscoord nsInputButtonFrame::GetVerticalInsidePadding(float aPixToTwip, 
                                                      nscoord aInnerHeight) const
 {
-  //return (int)(4 * aPixToTwip + 0.5);
+  //return NSIntPixelsToTwips(4, aPixToTwip);
 #ifdef XP_PC
-  return (nscoord)(aInnerHeight * .25 + 0.5);
+  return (nscoord)NSToIntRound((float)aInnerHeight * 0.25f);
 #endif
 #ifdef XP_UNIX
-  return (nscoord)(aInnerHeight * .50 + 0.5);
+  return (nscoord)NSToIntRound((float)aInnerHeight * 0.50f);
 #endif
 }
 
@@ -388,16 +388,16 @@ nscoord nsInputButtonFrame::GetHorizontalInsidePadding(float aPixToTwip,
 {
 #ifdef XP_PC
   if (kBackwardMode == GetMode()) {
-    return (nscoord)((aInnerWidth * .25) + 0.5);
+    return (nscoord)NSToIntRound(float(aInnerWidth) * 0.25f);
   } else {
-    return (nscoord)(10 * aPixToTwip + 0.5)+8;
+    return NSIntPixelsToTwips(10, aPixToTwip) + 8;
   }
 #endif
 #ifdef XP_UNIX
   if (kBackwardMode == GetMode()) {
-    return (nscoord)(aInnerWidth * .5 + 0.5);
+    return (nscoord)NSToIntRound(float(aInnerWidth) * 0.5f);
   } else {
-    return (nscoord)(20 * aPixToTwip + 0.5);
+    return NSIntPixelsToTwips(20, aPixToTwip);
   }
 #endif
 }
diff --git a/mozilla/layout/html/forms/src/nsInputCheckbox.cpp b/mozilla/layout/html/forms/src/nsInputCheckbox.cpp
index 94ceff8b1dc..8a33ffe2232 100644
--- a/mozilla/layout/html/forms/src/nsInputCheckbox.cpp
+++ b/mozilla/layout/html/forms/src/nsInputCheckbox.cpp
@@ -84,12 +84,12 @@ nsInputCheckboxFrame::GetDesiredSize(nsIPresContext* aPresContext,
 {
   float p2t = aPresContext->GetPixelsToTwips();
 #ifdef XP_PC
-  aDesiredWidgetSize.width  = (int)(12 * p2t);
-  aDesiredWidgetSize.height = (int)(12 * p2t);
+  aDesiredWidgetSize.width  = NSIntPixelsToTwips(12, p2t);
+  aDesiredWidgetSize.height = NSIntPixelsToTwips(12, p2t);
 #endif
 #ifdef XP_PC
-  aDesiredWidgetSize.width  = (int)(20 * p2t);
-  aDesiredWidgetSize.height = (int)(20 * p2t);
+  aDesiredWidgetSize.width  = NSIntPixelsToTwips(20, p2t);
+  aDesiredWidgetSize.height = NSIntPixelsToTwips(20, p2t);
 #endif
   aDesiredLayoutSize.width  = aDesiredWidgetSize.width;
   aDesiredLayoutSize.height = aDesiredWidgetSize.height;
@@ -158,7 +158,7 @@ void nsInputCheckbox::MapAttributesInto(nsIStyleContext* aContext,
                                      nsIPresContext* aPresContext)
 {
   float p2t = aPresContext->GetPixelsToTwips();
-  nscoord pad = (int)(3 * p2t + 0.5);
+  nscoord pad = NSIntPixelsToTwips(3, p2t);
 
   // add left and right padding around the radio button via css
   nsStyleSpacing* spacing = (nsStyleSpacing*) aContext->GetMutableStyleData(eStyleStruct_Spacing);
@@ -167,7 +167,7 @@ void nsInputCheckbox::MapAttributesInto(nsIStyleContext* aContext,
     spacing->mMargin.SetLeft(left);
   }
   if (eStyleUnit_Null == spacing->mMargin.GetRightUnit()) {
-    nsStyleCoord right((int)(5 * p2t + 0.5));
+    nsStyleCoord right(NSIntPixelsToTwips(5, p2t));
     spacing->mMargin.SetRight(right);
   }
   // add bottom padding if backward mode
diff --git a/mozilla/layout/html/forms/src/nsInputFrame.cpp b/mozilla/layout/html/forms/src/nsInputFrame.cpp
index f0bb098dca6..9a784a2ac80 100644
--- a/mozilla/layout/html/forms/src/nsInputFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsInputFrame.cpp
@@ -78,17 +78,17 @@ nsFormRenderingMode nsInputFrame::GetMode() const
   }
 }
 
-PRInt32 nsInputFrame::GetScrollbarWidth(float aPixToTwip)
+nscoord nsInputFrame::GetScrollbarWidth(float aPixToTwip)
 {
-   return (PRInt32)((19 * aPixToTwip) + 0.5);  // XXX this is windows
+   return NSIntPixelsToTwips(19, aPixToTwip);  // XXX this is windows
 }
 
-PRInt32 nsInputFrame::GetVerticalBorderWidth(float aPixToTwip) const
+nscoord nsInputFrame::GetVerticalBorderWidth(float aPixToTwip) const
 {
-   return (int)(3 * aPixToTwip + 0.5);
+   return NSIntPixelsToTwips(3, aPixToTwip);
 }
 
-PRInt32 nsInputFrame::GetHorizontalBorderWidth(float aPixToTwip) const
+nscoord nsInputFrame::GetHorizontalBorderWidth(float aPixToTwip) const
 {
   return GetVerticalBorderWidth(aPixToTwip);
 }
@@ -96,7 +96,7 @@ PRInt32 nsInputFrame::GetHorizontalBorderWidth(float aPixToTwip) const
 nscoord nsInputFrame::GetVerticalInsidePadding(float aPixToTwip, 
                                                nscoord aInnerHeight) const
 {
-   return (nscoord)(3 * aPixToTwip + 0.5);
+   return NSIntPixelsToTwips(3, aPixToTwip);
 }
 
 nscoord nsInputFrame::GetHorizontalInsidePadding(float aPixToTwip, 
@@ -398,9 +398,9 @@ NS_METHOD nsInputFrame::HandleEvent(nsIPresContext& aPresContext,
 		    widget->SetFocus();
 		    NS_RELEASE(widget);
 	      NS_RELEASE(view); */
-        float conv = aPresContext.GetTwipsToPixels();
-        ((nsInput*)mContent)->SetClickPoint(NS_TO_INT_ROUND(conv * aEvent->point.x),
-                                            NS_TO_INT_ROUND(conv * aEvent->point.y));   
+        float t2p = aPresContext.GetTwipsToPixels();
+        ((nsInput*)mContent)->SetClickPoint(NSTwipsToIntPixels(aEvent->point.x, t2p),
+                                            NSTwipsToIntPixels(aEvent->point.y, t2p));   
  		    MouseClicked(&aPresContext);
 		    //return PR_FALSE;
 	    } 
@@ -495,7 +495,7 @@ nsInputFrame::CalculateSize (nsIPresContext* aPresContext, nsInputFrame* aFrame,
   // determine the width
   if (eContentAttr_HasValue == colStatus) {  // col attr will provide width
     if (aSpec.mColSizeAttrInPixels) {
-      aBounds.width = (int) (((float)colAttr.GetPixelValue()) * p2t);
+      aBounds.width = NSIntPixelsToTwips(colAttr.GetPixelValue(), p2t);
     }
     else {
       PRInt32 col = ((colAttr.GetUnit() == eHTMLUnit_Pixel) ? colAttr.GetPixelValue() : colAttr.GetIntValue());
diff --git a/mozilla/layout/html/forms/src/nsInputFrame.h b/mozilla/layout/html/forms/src/nsInputFrame.h
index 7818553cb08..ced82b2ff31 100644
--- a/mozilla/layout/html/forms/src/nsInputFrame.h
+++ b/mozilla/layout/html/forms/src/nsInputFrame.h
@@ -171,9 +171,9 @@ public:
 
   // XXX similar functionality needs to be added to widget library and these
   //     need to change to use it.
-  static  PRInt32 GetScrollbarWidth(float aPixToTwip);
-  virtual PRInt32 GetVerticalBorderWidth(float aPixToTwip) const;
-  virtual PRInt32 GetHorizontalBorderWidth(float aPixToTwip) const;
+  static  nscoord GetScrollbarWidth(float aPixToTwip);
+  virtual nscoord GetVerticalBorderWidth(float aPixToTwip) const;
+  virtual nscoord GetHorizontalBorderWidth(float aPixToTwip) const;
   virtual nscoord GetVerticalInsidePadding(float aPixToTwip,
                                            nscoord aInnerHeight) const;
   virtual nscoord GetHorizontalInsidePadding(float aPixToTwip, 
diff --git a/mozilla/layout/html/forms/src/nsInputRadio.cpp b/mozilla/layout/html/forms/src/nsInputRadio.cpp
index 0f4ae98d6ac..4ba5ef5f2c0 100644
--- a/mozilla/layout/html/forms/src/nsInputRadio.cpp
+++ b/mozilla/layout/html/forms/src/nsInputRadio.cpp
@@ -87,8 +87,8 @@ nsInputRadioFrame::GetDesiredSize(nsIPresContext* aPresContext,
                                   nsSize& aDesiredWidgetSize)
 {
   float p2t = aPresContext->GetPixelsToTwips();
-  aDesiredWidgetSize.width  = (int)(12 * p2t);
-  aDesiredWidgetSize.height = (int)(12 * p2t);
+  aDesiredWidgetSize.width  = NSIntPixelsToTwips(12, p2t);
+  aDesiredWidgetSize.height = NSIntPixelsToTwips(12, p2t);
   aDesiredLayoutSize.width  = aDesiredWidgetSize.width;
   aDesiredLayoutSize.height = aDesiredWidgetSize.height;
   aDesiredLayoutSize.ascent = aDesiredLayoutSize.height;
@@ -139,7 +139,7 @@ void nsInputRadio::MapAttributesInto(nsIStyleContext* aContext,
                                      nsIPresContext* aPresContext)
 {
   float p2t = aPresContext->GetPixelsToTwips();
-  nscoord pad = (int)(3 * p2t + 0.5);
+  nscoord pad = NSIntPixelsToTwips(3, p2t);
 
   // add left and right padding around the radio button via css
   nsStyleSpacing* spacing = (nsStyleSpacing*) aContext->GetMutableStyleData(eStyleStruct_Spacing);
@@ -148,7 +148,7 @@ void nsInputRadio::MapAttributesInto(nsIStyleContext* aContext,
     spacing->mMargin.SetLeft(left);
   }
   if (eStyleUnit_Null == spacing->mMargin.GetRightUnit()) {
-    nsStyleCoord right((int)(5 * p2t + 0.5));
+    nsStyleCoord right(NSIntPixelsToTwips(5, p2t));
     spacing->mMargin.SetRight(right);
   }
   // add bottom padding if backward mode
diff --git a/mozilla/layout/html/forms/src/nsInputText.cpp b/mozilla/layout/html/forms/src/nsInputText.cpp
index 1102246a9cb..5b50d1dd392 100644
--- a/mozilla/layout/html/forms/src/nsInputText.cpp
+++ b/mozilla/layout/html/forms/src/nsInputText.cpp
@@ -49,8 +49,8 @@ public:
 
   virtual const nsIID& GetIID();
 
-  virtual PRInt32 GetVerticalBorderWidth(float aPixToTwip) const;
-  virtual PRInt32 GetHorizontalBorderWidth(float aPixToTwip) const;
+  virtual nscoord GetVerticalBorderWidth(float aPixToTwip) const;
+  virtual nscoord GetHorizontalBorderWidth(float aPixToTwip) const;
   virtual nscoord GetVerticalInsidePadding(float aPixToTwip,
                                            nscoord aInnerHeight) const;
   virtual nscoord GetHorizontalInsidePadding(float aPixToTwip, 
@@ -78,12 +78,12 @@ nsInputTextFrame::~nsInputTextFrame()
 {
 }
 
-PRInt32 nsInputTextFrame::GetVerticalBorderWidth(float aPixToTwip) const
+nscoord nsInputTextFrame::GetVerticalBorderWidth(float aPixToTwip) const
 {
-   return (int)(4 * aPixToTwip + 0.5);
+   return NSIntPixelsToTwips(4, aPixToTwip);
 }
 
-PRInt32 nsInputTextFrame::GetHorizontalBorderWidth(float aPixToTwip) const
+nscoord nsInputTextFrame::GetHorizontalBorderWidth(float aPixToTwip) const
 {
   return GetVerticalBorderWidth(aPixToTwip);
 }
@@ -96,13 +96,13 @@ nscoord nsInputTextFrame::GetVerticalInsidePadding(float aPixToTwip,
   nsAutoString type;
   ((nsInput*)mContent)->GetType(type);
   if (type.EqualsIgnoreCase("textarea")) {
-    return (nscoord)((aInnerHeight * .40) + 0.5);
+    return (nscoord)NSToIntRound(float(aInnerHeight) * 0.40f);
   } else {
-    return (nscoord)((aInnerHeight * .25) + 0.5);
+    return (nscoord)NSToIntRound(float(aInnerHeight) * 0.25f);
   }
 #endif
 #ifdef XP_UNIX
-  return (nscoord)(10 * aPixToTwip + 0.5); // XXX this is probably wrong
+  return NSIntPixelsToTwips(10, aPixToTwip); // XXX this is probably wrong
 #endif
 }
 
@@ -119,7 +119,7 @@ nscoord nsInputTextFrame::GetHorizontalInsidePadding(float aPixToTwip,
   } else {
     padding = (nscoord)(55 * aCharWidth / 100);
   }
-  nscoord min = (nscoord)((3 * aPixToTwip) + 0.5);
+  nscoord min = NSIntPixelsToTwips(3, aPixToTwip);
   if (padding > min) {
     return padding;
   } else {
@@ -127,7 +127,7 @@ nscoord nsInputTextFrame::GetHorizontalInsidePadding(float aPixToTwip,
   }
 #endif
 #ifdef XP_UNIX
-  return (nscoord)(6 * aPixToTwip + 0.5);  // XXX this is probably wrong
+  return NSIntPixelsToTwips(6, aPixToTwip);  // XXX this is probably wrong
 #endif
 }
 
@@ -210,7 +210,7 @@ nsInputTextFrame::GetDesiredSize(nsIPresContext* aPresContext,
 
   if (kInputText_Area == textType) {
     float p2t = aPresContext->GetPixelsToTwips();
-    PRInt32 scrollbarWidth = GetScrollbarWidth(p2t);
+    nscoord scrollbarWidth = GetScrollbarWidth(p2t);
 
     if (!heightExplicit) {
       size.height += scrollbarWidth;
diff --git a/mozilla/layout/html/forms/src/nsSelect.cpp b/mozilla/layout/html/forms/src/nsSelect.cpp
index 383a7ae1e9d..db141413e12 100644
--- a/mozilla/layout/html/forms/src/nsSelect.cpp
+++ b/mozilla/layout/html/forms/src/nsSelect.cpp
@@ -60,8 +60,8 @@ public:
 
   virtual const nsIID& GetIID();
 
-  virtual PRInt32 GetVerticalBorderWidth(float aPixToTwip) const;
-  virtual PRInt32 GetHorizontalBorderWidth(float aPixToTwip) const;
+  virtual nscoord GetVerticalBorderWidth(float aPixToTwip) const;
+  virtual nscoord GetHorizontalBorderWidth(float aPixToTwip) const;
   virtual nscoord GetVerticalInsidePadding(float aPixToTwip,
                                            nscoord aInnerHeight) const;
   virtual nscoord GetHorizontalInsidePadding(float aPixToTwip, 
@@ -163,12 +163,12 @@ nsSelectFrame::~nsSelectFrame()
 }
 
 
-PRInt32 nsSelectFrame::GetVerticalBorderWidth(float aPixToTwip) const
+nscoord nsSelectFrame::GetVerticalBorderWidth(float aPixToTwip) const
 {
-   return (int)(1 * aPixToTwip + 0.5);
+   return NSIntPixelsToTwips(1, aPixToTwip);
 }
 
-PRInt32 nsSelectFrame::GetHorizontalBorderWidth(float aPixToTwip) const
+nscoord nsSelectFrame::GetHorizontalBorderWidth(float aPixToTwip) const
 {
   return GetVerticalBorderWidth(aPixToTwip);
 }
@@ -177,10 +177,10 @@ nscoord nsSelectFrame::GetVerticalInsidePadding(float aPixToTwip,
                                                nscoord aInnerHeight) const
 {
 #ifdef XP_PC
-  return (nscoord)((aInnerHeight * .15) + 0.5);
+  return (nscoord)NSToIntRound(float(aInnerHeight) * 0.15f);
 #endif
 #ifdef XP_UNIX
-  return (nscoord)(1 * aPixToTwip + 0.5); // XXX this is probably wrong
+  return NSIntPixelsToTwips(1, aPixToTwip); // XXX this is probably wrong
 #endif
 }
 
@@ -189,8 +189,8 @@ PRInt32 nsSelectFrame::GetHorizontalInsidePadding(float aPixToTwip,
                                                  nscoord aCharWidth) const
 {
 #ifdef XP_PC
-  nscoord padding = (nscoord)((aCharWidth * .40) + 0.5);
-  nscoord min = (nscoord)((3 * aPixToTwip) + 0.5);
+  nscoord padding = (nscoord)NSToIntRound(float(aCharWidth) * 0.40f);
+  nscoord min = NSIntPixelsToTwips(3, aPixToTwip);
   if (padding > min) {
     return padding;
   } else {
@@ -198,7 +198,7 @@ PRInt32 nsSelectFrame::GetHorizontalInsidePadding(float aPixToTwip,
   }
 #endif
 #ifdef XP_UNIX
-  return (nscoord)(7 * aPixToTwip + 0.5); // XXX this is probably wrong
+  return NSIntPixelsToTwips(7, aPixToTwip); // XXX this is probably wrong
 #endif
 }
 
@@ -303,7 +303,7 @@ nsSelectFrame::GetWidgetInitData(nsIPresContext& aPresContext)
   if (select->mIsComboBox) {
     nsComboBoxInitData* initData = new nsComboBoxInitData();
     float twipToPix = aPresContext.GetTwipsToPixels();
-    initData->mDropDownHeight = NS_TO_INT_ROUND(mWidgetSize.height * twipToPix);
+    initData->mDropDownHeight = NSTwipsToIntPixels(mWidgetSize.height, twipToPix);
     return initData;
   }
   else {
diff --git a/mozilla/layout/html/style/src/nsCSSDeclaration.cpp b/mozilla/layout/html/style/src/nsCSSDeclaration.cpp
index 38f4f48d504..9043f5df4c3 100644
--- a/mozilla/layout/html/style/src/nsCSSDeclaration.cpp
+++ b/mozilla/layout/html/style/src/nsCSSDeclaration.cpp
@@ -322,29 +322,29 @@ nscoord nsCSSValue::GetLengthTwips(void) const
   if (IsFixedLengthUnit()) {
     switch (mUnit) {
     case eCSSUnit_Inch:        
-      return (nscoord)NS_INCHES_TO_TWIPS(mValue.mFloat);
+      return NS_INCHES_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Foot:        
-      return (nscoord)NS_FEET_TO_TWIPS(mValue.mFloat);
+      return NS_FEET_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Mile:        
-      return (nscoord)NS_MILES_TO_TWIPS(mValue.mFloat);
+      return NS_MILES_TO_TWIPS(mValue.mFloat);
 
     case eCSSUnit_Millimeter:
-      return (nscoord)NS_MILLIMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_MILLIMETERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Centimeter:
-      return (nscoord)NS_CENTIMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_CENTIMETERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Meter:
-      return (nscoord)NS_METERS_TO_TWIPS(mValue.mFloat);
+      return NS_METERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Kilometer:
-      return (nscoord)NS_KILOMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_KILOMETERS_TO_TWIPS(mValue.mFloat);
 
     case eCSSUnit_Point:
-      return (nscoord)NS_POINTS_TO_TWIPS_FLOAT(mValue.mFloat);
+      return NSFloatPointsToTwips(mValue.mFloat);
     case eCSSUnit_Pica:
-      return (nscoord)NS_PICAS_TO_TWIPS(mValue.mFloat);
+      return NS_PICAS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Didot:
-      return (nscoord)NS_DIDOTS_TO_TWIPS(mValue.mFloat);
+      return NS_DIDOTS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Cicero:
-      return (nscoord)NS_CICEROS_TO_TWIPS(mValue.mFloat);
+      return NS_CICEROS_TO_TWIPS(mValue.mFloat);
     }
   }
   return 0;
diff --git a/mozilla/layout/html/style/src/nsCSSRendering.cpp b/mozilla/layout/html/style/src/nsCSSRendering.cpp
index 55a04c0543d..1987d833978 100644
--- a/mozilla/layout/html/style/src/nsCSSRendering.cpp
+++ b/mozilla/layout/html/style/src/nsCSSRendering.cpp
@@ -693,8 +693,8 @@ void nsCSSRendering::PaintBackground(nsIPresContext& aPresContext,
 
     // Convert image dimensions into nscoord's
     float p2t = aPresContext.GetPixelsToTwips();
-    nscoord tileWidth = nscoord(p2t * imageSize.width);
-    nscoord tileHeight = nscoord(p2t * imageSize.height);
+    nscoord tileWidth = NSIntPixelsToTwips(imageSize.width, p2t);
+    nscoord tileHeight = NSIntPixelsToTwips(imageSize.height, p2t);
 
     PRIntn repeat = aColor.mBackgroundRepeat;
     PRIntn xcount, ycount;
diff --git a/mozilla/layout/html/style/src/nsCSSStyleRule.cpp b/mozilla/layout/html/style/src/nsCSSStyleRule.cpp
index 7eb2e08fd41..3e2b6f680c0 100644
--- a/mozilla/layout/html/style/src/nsCSSStyleRule.cpp
+++ b/mozilla/layout/html/style/src/nsCSSStyleRule.cpp
@@ -438,7 +438,7 @@ nscoord CSSStyleRuleImpl::CalcLength(const nsCSSValue& aValue,
       return ((aFont->mFont.size / 3) * 2); // XXX HACK!
 
     case eCSSUnit_Pixel:
-      return (nscoord)(aPresContext->GetPixelsToTwips() * aValue.GetFloatValue());
+      return NSFloatPixelsToTwips(aValue.GetFloatValue(), aPresContext->GetPixelsToTwips());
   }
   return 0;
 }
diff --git a/mozilla/layout/html/style/src/nsStyleUtil.cpp b/mozilla/layout/html/style/src/nsStyleUtil.cpp
index 50e443f4b25..1ab34d8949a 100644
--- a/mozilla/layout/html/style/src/nsStyleUtil.cpp
+++ b/mozilla/layout/html/style/src/nsStyleUtil.cpp
@@ -48,7 +48,7 @@ float nsStyleUtil::GetScalingFactor(PRInt32 aScaler)
     scale *= mult;
   }
 
-  return scale;
+  return (float)scale;
 }
 
 /*
diff --git a/mozilla/layout/html/table/src/nsTableCell.cpp b/mozilla/layout/html/table/src/nsTableCell.cpp
index 6ddf06d655f..81dee9edc77 100644
--- a/mozilla/layout/html/table/src/nsTableCell.cpp
+++ b/mozilla/layout/html/table/src/nsTableCell.cpp
@@ -336,7 +336,7 @@ void nsTableCell::MapAttributesInto(nsIStyleContext* aContext,
     aContext->GetMutableStyleData(eStyleStruct_Position);
   GetAttribute(nsHTMLAtoms::width, widthValue);
   if (widthValue.GetUnit() == eHTMLUnit_Pixel) {
-    nscoord twips = nscoord(p2t * widthValue.GetPixelValue());
+    nscoord twips = NSIntPixelsToTwips(widthValue.GetPixelValue(), p2t);
     pos->mWidth.SetCoordValue(twips);
   }
   else if (widthValue.GetUnit() == eHTMLUnit_Percent) {
@@ -346,7 +346,7 @@ void nsTableCell::MapAttributesInto(nsIStyleContext* aContext,
   // height: pixel
   GetAttribute(nsHTMLAtoms::height, value);
   if (value.GetUnit() == eHTMLUnit_Pixel) {
-    nscoord twips = nscoord(p2t * value.GetPixelValue());
+    nscoord twips = NSIntPixelsToTwips(value.GetPixelValue(), p2t);
     pos->mHeight.SetCoordValue(twips);
   }
 
diff --git a/mozilla/layout/html/table/src/nsTableCellFrame.cpp b/mozilla/layout/html/table/src/nsTableCellFrame.cpp
index ae226212813..45247adb7a7 100644
--- a/mozilla/layout/html/table/src/nsTableCellFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableCellFrame.cpp
@@ -362,7 +362,7 @@ NS_METHOD nsTableCellFrame::Reflow(nsIPresContext& aPresContext,
       grandChild->ChildCount(childCount);
       if (0!=childCount)
       {
-        nscoord one = ((nscoord)(NS_INT_PIXELS_TO_TWIPS(1, aPresContext.GetPixelsToTwips())));
+        nscoord one = ((nscoord)(NSIntPixelsToTwips(1, aPresContext.GetPixelsToTwips())));
         cellWidth = 1;
         if (gsDebug) 
           printf ("setting cellWidth=1 because it was 0 but there's some content\n");
@@ -502,8 +502,6 @@ void nsTableCellFrame::MapBorderMarginPadding(nsIPresContext* aPresContext)
   nscoord   spacing = 0;
   nscoord   border  = 1;
 
-  float     p2t = aPresContext->GetPixelsToTwips();
-
   nsTableFrame*  tableFrame = GetTableFrame();
   tableFrame->GetGeometricParent((nsIFrame *&)tableFrame); // get the outer frame
   NS_ASSERTION(tableFrame,"Table Must not be null");
@@ -539,7 +537,7 @@ void nsTableCellFrame::MapBorderMarginPadding(nsIPresContext* aPresContext)
     if (0!=borderWidth.GetCoordValue())
     {
       // in HTML, cell borders are always 1 pixel by default
-      border = (nscoord)(1*(aPresContext->GetPixelsToTwips()));
+      border = NSIntPixelsToTwips(1, aPresContext->GetPixelsToTwips());
       MapHTMLBorderStyle(aPresContext, *spacingData, border);
     }
   }
@@ -1063,10 +1061,10 @@ void nsTableCellFrame::List(FILE* out, PRInt32 aIndent) const
     */
     for (indent = aIndent; --indent >= 0; ) fputs("  ", out);
     fprintf(out,"Margin -- Top: %d Left: %d Bottom: %d Right: %d \n",  
-                NS_TWIPS_TO_POINTS_INT(mMargin.top),
-                NS_TWIPS_TO_POINTS_INT(mMargin.left),
-                NS_TWIPS_TO_POINTS_INT(mMargin.bottom),
-                NS_TWIPS_TO_POINTS_INT(mMargin.right));
+                NSTwipsToIntPoints(mMargin.top),
+                NSTwipsToIntPoints(mMargin.left),
+                NSTwipsToIntPoints(mMargin.bottom),
+                NSTwipsToIntPoints(mMargin.right));
 
 
     for (indent = aIndent; --indent >= 0; ) fputs("  ", out);
@@ -1080,10 +1078,10 @@ void nsTableCellFrame::List(FILE* out, PRInt32 aIndent) const
 
 
     fprintf(out,"Border -- Top: %d Left: %d Bottom: %d Right: %d \n",  
-                NS_TWIPS_TO_POINTS_INT(top),
-                NS_TWIPS_TO_POINTS_INT(left),
-                NS_TWIPS_TO_POINTS_INT(bottom),
-                NS_TWIPS_TO_POINTS_INT(right));
+                NSTwipsToIntPoints(top),
+                NSTwipsToIntPoints(left),
+                NSTwipsToIntPoints(bottom),
+                NSTwipsToIntPoints(right));
 
 
 
diff --git a/mozilla/layout/html/table/src/nsTableCol.cpp b/mozilla/layout/html/table/src/nsTableCol.cpp
index 9b966c09a43..e881e424cd7 100644
--- a/mozilla/layout/html/table/src/nsTableCol.cpp
+++ b/mozilla/layout/html/table/src/nsTableCol.cpp
@@ -146,7 +146,7 @@ void nsTableCol::MapAttributesInto(nsIStyleContext* aContext,
 
       case eHTMLUnit_Pixel:
         p2t = aPresContext->GetPixelsToTwips();
-        position->mWidth.SetCoordValue(nscoord(p2t * (float)value.GetPixelValue()));
+        position->mWidth.SetCoordValue(NSIntPixelsToTwips(value.GetPixelValue(), p2t));
         break;
       }
     }
diff --git a/mozilla/layout/html/table/src/nsTableColGroup.cpp b/mozilla/layout/html/table/src/nsTableColGroup.cpp
index 4be6ed4eeb5..f7ad092e9ea 100644
--- a/mozilla/layout/html/table/src/nsTableColGroup.cpp
+++ b/mozilla/layout/html/table/src/nsTableColGroup.cpp
@@ -321,7 +321,7 @@ void nsTableColGroup::MapAttributesInto(nsIStyleContext* aContext,
 
       case eHTMLUnit_Pixel:
         p2t = aPresContext->GetPixelsToTwips();
-        position->mWidth.SetCoordValue(nscoord(p2t * (float)value.GetPixelValue()));
+        position->mWidth.SetCoordValue(NSIntPixelsToTwips(value.GetPixelValue(), p2t));
         break;
       }
     }
diff --git a/mozilla/layout/html/table/src/nsTableFrame.cpp b/mozilla/layout/html/table/src/nsTableFrame.cpp
index 820d17f6d71..4c16f63c6c3 100644
--- a/mozilla/layout/html/table/src/nsTableFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableFrame.cpp
@@ -899,10 +899,10 @@ void nsTableFrame::ListColumnLayoutData(FILE* out, PRInt32 aIndent)
         nsMargin margin;
         cellFrame->GetMargin(margin);
         fprintf(out,"Margin -- Top: %d Left: %d Bottom: %d Right: %d \n",  
-                NS_TWIPS_TO_POINTS_INT(margin.top),
-                NS_TWIPS_TO_POINTS_INT(margin.left),
-                NS_TWIPS_TO_POINTS_INT(margin.bottom),
-                NS_TWIPS_TO_POINTS_INT(margin.right));
+                NSTwipsToIntPoints(margin.top),
+                NSTwipsToIntPoints(margin.left),
+                NSTwipsToIntPoints(margin.bottom),
+                NSTwipsToIntPoints(margin.right));
       
         for (rowIndent = aIndent+2; --rowIndent >= 0; ) fputs("  ", out);
 
@@ -914,10 +914,10 @@ void nsTableFrame::ListColumnLayoutData(FILE* out, PRInt32 aIndent)
         right = (mBorderFrame[NS_SIDE_RIGHT] ? cellFrame->GetBorderWidth((nsIFrame*)mBorderFrame[NS_SIDE_RIGHT], NS_SIDE_RIGHT) : 0);
 
         fprintf(out,"Border -- Top: %d Left: %d Bottom: %d Right: %d \n",  
-                    NS_TWIPS_TO_POINTS_INT(top),
-                    NS_TWIPS_TO_POINTS_INT(left),
-                    NS_TWIPS_TO_POINTS_INT(bottom),
-                    NS_TWIPS_TO_POINTS_INT(right));
+                    NSTwipsToIntPoints(top),
+                    NSTwipsToIntPoints(left),
+                    NSTwipsToIntPoints(bottom),
+                    NSTwipsToIntPoints(right));
     */
       }
     }
@@ -2906,7 +2906,7 @@ void nsTableFrame::MapBorderMarginPadding(nsIPresContext* aPresContext)
     PRInt32 intValue = 0;
 
     if (ConvertToPixelValue(border_value,1,intValue))
-      border = nscoord(p2t*(float)intValue); 
+      border = NSIntPixelsToTwips(intValue, p2t); 
   }
   MapHTMLBorderStyle(*spacingData,border);
 }
diff --git a/mozilla/layout/html/table/src/nsTablePart.cpp b/mozilla/layout/html/table/src/nsTablePart.cpp
index b8d12be4c52..f86de8dcacb 100644
--- a/mozilla/layout/html/table/src/nsTablePart.cpp
+++ b/mozilla/layout/html/table/src/nsTablePart.cpp
@@ -678,7 +678,7 @@ void nsTablePart::MapAttributesInto(nsIStyleContext* aContext,
       break;
 
     case eHTMLUnit_Pixel:
-      position->mWidth.SetCoordValue(nscoord(p2t * (float)value.GetPixelValue()));
+      position->mWidth.SetCoordValue(NSIntPixelsToTwips(value.GetPixelValue(), p2t));
       break;
     }
   }
@@ -707,7 +707,7 @@ void nsTablePart::MapAttributesInto(nsIStyleContext* aContext,
   GetAttribute(nsHTMLAtoms::cellpadding, value);
   if (value.GetUnit() != eHTMLUnit_Null) {
     tableStyle = (nsStyleTable*)aContext->GetMutableStyleData(eStyleStruct_Table);
-    tableStyle->mCellPadding.SetCoordValue((nscoord)(p2t*(float)(value.GetPixelValue())));
+    tableStyle->mCellPadding.SetCoordValue(NSIntPixelsToTwips(value.GetPixelValue(), p2t));
   }
 
   // cellspacing  (reuses tableStyle if already resolved)
@@ -715,13 +715,13 @@ void nsTablePart::MapAttributesInto(nsIStyleContext* aContext,
   if (value.GetUnit() != eHTMLUnit_Null) {
     if (nsnull==tableStyle)
       tableStyle = (nsStyleTable*)aContext->GetMutableStyleData(eStyleStruct_Table);
-    tableStyle->mCellSpacing.SetCoordValue((nscoord)(p2t*(float)(value.GetPixelValue())));
+    tableStyle->mCellSpacing.SetCoordValue(NSIntPixelsToTwips(value.GetPixelValue(), p2t));
   }
   else
   { // XXX: remove me as soon as we get this from the style sheet
     if (nsnull==tableStyle)
       tableStyle = (nsStyleTable*)aContext->GetMutableStyleData(eStyleStruct_Table);
-    tableStyle->mCellSpacing.SetCoordValue((nscoord)(p2t*(float)2));
+    tableStyle->mCellSpacing.SetCoordValue(NSIntPixelsToTwips(2, p2t));
   }
 
   // cols
@@ -757,14 +757,14 @@ void nsTablePart::GetTableBorder(nsIHTMLContent* aContent,
     float p2t = aPresContext->GetPixelsToTwips();
     nsStyleCoord twips;
     if (value.GetUnit() == eHTMLUnit_Empty) {
-      twips.SetCoordValue(nscoord(NS_INT_PIXELS_TO_TWIPS(1, p2t)));
+      twips.SetCoordValue(NSIntPixelsToTwips(1, p2t));
     }
     else {
-      twips.SetCoordValue(nscoord(NS_INT_PIXELS_TO_TWIPS(value.GetPixelValue(), p2t)));
+      twips.SetCoordValue(NSIntPixelsToTwips(value.GetPixelValue(), p2t));
     }
 
 #if 0
-    nsStyleCoord  two(nscoord(NS_INT_PIXELS_TO_TWIPS(2,p2t)));
+    nsStyleCoord  two(NSIntPixelsToTwips(2, p2t));
 
     spacing->mPadding.SetTop(two);
     spacing->mPadding.SetRight(two);
diff --git a/mozilla/layout/style/nsCSSDeclaration.cpp b/mozilla/layout/style/nsCSSDeclaration.cpp
index 38f4f48d504..9043f5df4c3 100644
--- a/mozilla/layout/style/nsCSSDeclaration.cpp
+++ b/mozilla/layout/style/nsCSSDeclaration.cpp
@@ -322,29 +322,29 @@ nscoord nsCSSValue::GetLengthTwips(void) const
   if (IsFixedLengthUnit()) {
     switch (mUnit) {
     case eCSSUnit_Inch:        
-      return (nscoord)NS_INCHES_TO_TWIPS(mValue.mFloat);
+      return NS_INCHES_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Foot:        
-      return (nscoord)NS_FEET_TO_TWIPS(mValue.mFloat);
+      return NS_FEET_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Mile:        
-      return (nscoord)NS_MILES_TO_TWIPS(mValue.mFloat);
+      return NS_MILES_TO_TWIPS(mValue.mFloat);
 
     case eCSSUnit_Millimeter:
-      return (nscoord)NS_MILLIMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_MILLIMETERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Centimeter:
-      return (nscoord)NS_CENTIMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_CENTIMETERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Meter:
-      return (nscoord)NS_METERS_TO_TWIPS(mValue.mFloat);
+      return NS_METERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Kilometer:
-      return (nscoord)NS_KILOMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_KILOMETERS_TO_TWIPS(mValue.mFloat);
 
     case eCSSUnit_Point:
-      return (nscoord)NS_POINTS_TO_TWIPS_FLOAT(mValue.mFloat);
+      return NSFloatPointsToTwips(mValue.mFloat);
     case eCSSUnit_Pica:
-      return (nscoord)NS_PICAS_TO_TWIPS(mValue.mFloat);
+      return NS_PICAS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Didot:
-      return (nscoord)NS_DIDOTS_TO_TWIPS(mValue.mFloat);
+      return NS_DIDOTS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Cicero:
-      return (nscoord)NS_CICEROS_TO_TWIPS(mValue.mFloat);
+      return NS_CICEROS_TO_TWIPS(mValue.mFloat);
     }
   }
   return 0;
diff --git a/mozilla/layout/style/nsCSSStruct.cpp b/mozilla/layout/style/nsCSSStruct.cpp
index 38f4f48d504..9043f5df4c3 100644
--- a/mozilla/layout/style/nsCSSStruct.cpp
+++ b/mozilla/layout/style/nsCSSStruct.cpp
@@ -322,29 +322,29 @@ nscoord nsCSSValue::GetLengthTwips(void) const
   if (IsFixedLengthUnit()) {
     switch (mUnit) {
     case eCSSUnit_Inch:        
-      return (nscoord)NS_INCHES_TO_TWIPS(mValue.mFloat);
+      return NS_INCHES_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Foot:        
-      return (nscoord)NS_FEET_TO_TWIPS(mValue.mFloat);
+      return NS_FEET_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Mile:        
-      return (nscoord)NS_MILES_TO_TWIPS(mValue.mFloat);
+      return NS_MILES_TO_TWIPS(mValue.mFloat);
 
     case eCSSUnit_Millimeter:
-      return (nscoord)NS_MILLIMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_MILLIMETERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Centimeter:
-      return (nscoord)NS_CENTIMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_CENTIMETERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Meter:
-      return (nscoord)NS_METERS_TO_TWIPS(mValue.mFloat);
+      return NS_METERS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Kilometer:
-      return (nscoord)NS_KILOMETERS_TO_TWIPS(mValue.mFloat);
+      return NS_KILOMETERS_TO_TWIPS(mValue.mFloat);
 
     case eCSSUnit_Point:
-      return (nscoord)NS_POINTS_TO_TWIPS_FLOAT(mValue.mFloat);
+      return NSFloatPointsToTwips(mValue.mFloat);
     case eCSSUnit_Pica:
-      return (nscoord)NS_PICAS_TO_TWIPS(mValue.mFloat);
+      return NS_PICAS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Didot:
-      return (nscoord)NS_DIDOTS_TO_TWIPS(mValue.mFloat);
+      return NS_DIDOTS_TO_TWIPS(mValue.mFloat);
     case eCSSUnit_Cicero:
-      return (nscoord)NS_CICEROS_TO_TWIPS(mValue.mFloat);
+      return NS_CICEROS_TO_TWIPS(mValue.mFloat);
     }
   }
   return 0;
diff --git a/mozilla/layout/style/nsCSSStyleRule.cpp b/mozilla/layout/style/nsCSSStyleRule.cpp
index 7eb2e08fd41..3e2b6f680c0 100644
--- a/mozilla/layout/style/nsCSSStyleRule.cpp
+++ b/mozilla/layout/style/nsCSSStyleRule.cpp
@@ -438,7 +438,7 @@ nscoord CSSStyleRuleImpl::CalcLength(const nsCSSValue& aValue,
       return ((aFont->mFont.size / 3) * 2); // XXX HACK!
 
     case eCSSUnit_Pixel:
-      return (nscoord)(aPresContext->GetPixelsToTwips() * aValue.GetFloatValue());
+      return NSFloatPixelsToTwips(aValue.GetFloatValue(), aPresContext->GetPixelsToTwips());
   }
   return 0;
 }
diff --git a/mozilla/layout/style/nsStyleContext.cpp b/mozilla/layout/style/nsStyleContext.cpp
index cd3514441f9..a520fa357f4 100644
--- a/mozilla/layout/style/nsStyleContext.cpp
+++ b/mozilla/layout/style/nsStyleContext.cpp
@@ -245,9 +245,9 @@ void nsStyleSpacing::CalcPaddingFor(const nsIFrame* aFrame, nsMargin& aPadding)
 }
 
 static const nscoord kBorderWidths[3] = 
-  { NS_POINTS_TO_TWIPS_INT(1), 
-    NS_POINTS_TO_TWIPS_INT(3), 
-    NS_POINTS_TO_TWIPS_INT(5) };
+  { NSIntPointsToTwips(1), 
+    NSIntPointsToTwips(3), 
+    NSIntPointsToTwips(5) };
 
 void nsStyleSpacing::CalcBorderFor(const nsIFrame* aFrame, nsMargin& aBorder) const
 {
diff --git a/mozilla/layout/style/nsStyleUtil.cpp b/mozilla/layout/style/nsStyleUtil.cpp
index 50e443f4b25..1ab34d8949a 100644
--- a/mozilla/layout/style/nsStyleUtil.cpp
+++ b/mozilla/layout/style/nsStyleUtil.cpp
@@ -48,7 +48,7 @@ float nsStyleUtil::GetScalingFactor(PRInt32 aScaler)
     scale *= mult;
   }
 
-  return scale;
+  return (float)scale;
 }
 
 /*
diff --git a/mozilla/layout/tables/nsTableCellFrame.cpp b/mozilla/layout/tables/nsTableCellFrame.cpp
index ae226212813..45247adb7a7 100644
--- a/mozilla/layout/tables/nsTableCellFrame.cpp
+++ b/mozilla/layout/tables/nsTableCellFrame.cpp
@@ -362,7 +362,7 @@ NS_METHOD nsTableCellFrame::Reflow(nsIPresContext& aPresContext,
       grandChild->ChildCount(childCount);
       if (0!=childCount)
       {
-        nscoord one = ((nscoord)(NS_INT_PIXELS_TO_TWIPS(1, aPresContext.GetPixelsToTwips())));
+        nscoord one = ((nscoord)(NSIntPixelsToTwips(1, aPresContext.GetPixelsToTwips())));
         cellWidth = 1;
         if (gsDebug) 
           printf ("setting cellWidth=1 because it was 0 but there's some content\n");
@@ -502,8 +502,6 @@ void nsTableCellFrame::MapBorderMarginPadding(nsIPresContext* aPresContext)
   nscoord   spacing = 0;
   nscoord   border  = 1;
 
-  float     p2t = aPresContext->GetPixelsToTwips();
-
   nsTableFrame*  tableFrame = GetTableFrame();
   tableFrame->GetGeometricParent((nsIFrame *&)tableFrame); // get the outer frame
   NS_ASSERTION(tableFrame,"Table Must not be null");
@@ -539,7 +537,7 @@ void nsTableCellFrame::MapBorderMarginPadding(nsIPresContext* aPresContext)
     if (0!=borderWidth.GetCoordValue())
     {
       // in HTML, cell borders are always 1 pixel by default
-      border = (nscoord)(1*(aPresContext->GetPixelsToTwips()));
+      border = NSIntPixelsToTwips(1, aPresContext->GetPixelsToTwips());
       MapHTMLBorderStyle(aPresContext, *spacingData, border);
     }
   }
@@ -1063,10 +1061,10 @@ void nsTableCellFrame::List(FILE* out, PRInt32 aIndent) const
     */
     for (indent = aIndent; --indent >= 0; ) fputs("  ", out);
     fprintf(out,"Margin -- Top: %d Left: %d Bottom: %d Right: %d \n",  
-                NS_TWIPS_TO_POINTS_INT(mMargin.top),
-                NS_TWIPS_TO_POINTS_INT(mMargin.left),
-                NS_TWIPS_TO_POINTS_INT(mMargin.bottom),
-                NS_TWIPS_TO_POINTS_INT(mMargin.right));
+                NSTwipsToIntPoints(mMargin.top),
+                NSTwipsToIntPoints(mMargin.left),
+                NSTwipsToIntPoints(mMargin.bottom),
+                NSTwipsToIntPoints(mMargin.right));
 
 
     for (indent = aIndent; --indent >= 0; ) fputs("  ", out);
@@ -1080,10 +1078,10 @@ void nsTableCellFrame::List(FILE* out, PRInt32 aIndent) const
 
 
     fprintf(out,"Border -- Top: %d Left: %d Bottom: %d Right: %d \n",  
-                NS_TWIPS_TO_POINTS_INT(top),
-                NS_TWIPS_TO_POINTS_INT(left),
-                NS_TWIPS_TO_POINTS_INT(bottom),
-                NS_TWIPS_TO_POINTS_INT(right));
+                NSTwipsToIntPoints(top),
+                NSTwipsToIntPoints(left),
+                NSTwipsToIntPoints(bottom),
+                NSTwipsToIntPoints(right));
 
 
 
diff --git a/mozilla/layout/tables/nsTableFrame.cpp b/mozilla/layout/tables/nsTableFrame.cpp
index 820d17f6d71..4c16f63c6c3 100644
--- a/mozilla/layout/tables/nsTableFrame.cpp
+++ b/mozilla/layout/tables/nsTableFrame.cpp
@@ -899,10 +899,10 @@ void nsTableFrame::ListColumnLayoutData(FILE* out, PRInt32 aIndent)
         nsMargin margin;
         cellFrame->GetMargin(margin);
         fprintf(out,"Margin -- Top: %d Left: %d Bottom: %d Right: %d \n",  
-                NS_TWIPS_TO_POINTS_INT(margin.top),
-                NS_TWIPS_TO_POINTS_INT(margin.left),
-                NS_TWIPS_TO_POINTS_INT(margin.bottom),
-                NS_TWIPS_TO_POINTS_INT(margin.right));
+                NSTwipsToIntPoints(margin.top),
+                NSTwipsToIntPoints(margin.left),
+                NSTwipsToIntPoints(margin.bottom),
+                NSTwipsToIntPoints(margin.right));
       
         for (rowIndent = aIndent+2; --rowIndent >= 0; ) fputs("  ", out);
 
@@ -914,10 +914,10 @@ void nsTableFrame::ListColumnLayoutData(FILE* out, PRInt32 aIndent)
         right = (mBorderFrame[NS_SIDE_RIGHT] ? cellFrame->GetBorderWidth((nsIFrame*)mBorderFrame[NS_SIDE_RIGHT], NS_SIDE_RIGHT) : 0);
 
         fprintf(out,"Border -- Top: %d Left: %d Bottom: %d Right: %d \n",  
-                    NS_TWIPS_TO_POINTS_INT(top),
-                    NS_TWIPS_TO_POINTS_INT(left),
-                    NS_TWIPS_TO_POINTS_INT(bottom),
-                    NS_TWIPS_TO_POINTS_INT(right));
+                    NSTwipsToIntPoints(top),
+                    NSTwipsToIntPoints(left),
+                    NSTwipsToIntPoints(bottom),
+                    NSTwipsToIntPoints(right));
     */
       }
     }
@@ -2906,7 +2906,7 @@ void nsTableFrame::MapBorderMarginPadding(nsIPresContext* aPresContext)
     PRInt32 intValue = 0;
 
     if (ConvertToPixelValue(border_value,1,intValue))
-      border = nscoord(p2t*(float)intValue); 
+      border = NSIntPixelsToTwips(intValue, p2t); 
   }
   MapHTMLBorderStyle(*spacingData,border);
 }
diff --git a/mozilla/view/src/nsScrollingView.cpp b/mozilla/view/src/nsScrollingView.cpp
index 19f4cfd4186..5b93148ba97 100644
--- a/mozilla/view/src/nsScrollingView.cpp
+++ b/mozilla/view/src/nsScrollingView.cpp
@@ -33,6 +33,9 @@ static NS_DEFINE_IID(kIScrollbarIID, NS_ISCROLLBAR_IID);
 static NS_DEFINE_IID(kIScrollableViewIID, NS_ISCROLLABLEVIEW_IID);
 static NS_DEFINE_IID(kWidgetCID, NS_CHILD_CID);
 
+#define NS_TO_INT_ROUND(x)            ((PRInt32)floor((x) + 0.5))
+#define NS_POINTS_TO_TWIPS_INT(x)     ((PRInt32)(20 * (x)))
+
 class ScrollBarView : public nsView
 {
 public:
diff --git a/mozilla/view/src/nsView.cpp b/mozilla/view/src/nsView.cpp
index f091cd6d53f..fdf5c6d148c 100644
--- a/mozilla/view/src/nsView.cpp
+++ b/mozilla/view/src/nsView.cpp
@@ -85,8 +85,8 @@ nsEventStatus PR_CALLBACK HandleEvent(nsGUIEvent *aEvent)
 
             NS_RELEASE(scrollView);
 
-            if ((width == NS_TO_INT_ROUND(sizex * t2p)) &&
-                (height == NS_TO_INT_ROUND(sizey * t2p)))
+            if ((width == NSTwipsToIntPixels(sizex, t2p)) &&
+                (height == NSTwipsToIntPixels(sizey, t2p)))
             {
               NS_IF_RELEASE(rootView);
               NS_RELEASE(presContext);
@@ -95,8 +95,8 @@ nsEventStatus PR_CALLBACK HandleEvent(nsGUIEvent *aEvent)
             }
           }
 
-          vm->SetWindowDimensions(NS_TO_INT_ROUND(width * p2t),
-                                  NS_TO_INT_ROUND(height * p2t));
+          vm->SetWindowDimensions(NSIntPixelsToTwips(width, p2t),
+                                  NSIntPixelsToTwips(height, p2t));
           result = nsEventStatus_eConsumeNoDefault;
         }
 
@@ -143,15 +143,15 @@ nsEventStatus PR_CALLBACK HandleEvent(nsGUIEvent *aEvent)
 
         // pass on to view somewhere else to deal with
 
-        aEvent->point.x = NS_TO_INT_ROUND(aEvent->point.x * cx->GetPixelsToTwips());
-        aEvent->point.y = NS_TO_INT_ROUND(aEvent->point.y * cx->GetPixelsToTwips());
+        aEvent->point.x = NSIntPixelsToTwips(aEvent->point.x, cx->GetPixelsToTwips());
+        aEvent->point.y = NSIntPixelsToTwips(aEvent->point.y, cx->GetPixelsToTwips());
 
         result = view->HandleEvent(aEvent, NS_VIEW_FLAG_CHECK_CHILDREN | 
                                            NS_VIEW_FLAG_CHECK_PARENT |
                                            NS_VIEW_FLAG_CHECK_SIBLINGS);
 
-        aEvent->point.x = NS_TO_INT_ROUND(aEvent->point.x * cx->GetTwipsToPixels());
-        aEvent->point.y = NS_TO_INT_ROUND(aEvent->point.y * cx->GetTwipsToPixels());
+        aEvent->point.x = NSTwipsToIntPixels(aEvent->point.x, cx->GetTwipsToPixels());
+        aEvent->point.y = NSTwipsToIntPixels(aEvent->point.y, cx->GetTwipsToPixels());
 
         NS_RELEASE(cx);
         NS_RELEASE(vm);
@@ -726,8 +726,8 @@ void nsView :: SetPosition(nscoord x, nscoord y)
     pwidget = GetOffsetFromWidget(&parx, &pary);
     NS_IF_RELEASE(pwidget);
     
-    mWindow->Move(NS_TO_INT_ROUND((x + parx + offx) * scale),
-                  NS_TO_INT_ROUND((y + pary + offy) * scale));
+    mWindow->Move(NSTwipsToIntPixels((x + parx + offx), scale),
+                  NSTwipsToIntPixels((y + pary + offy), scale));
 
     NS_RELEASE(px);
   }
@@ -770,7 +770,7 @@ void nsView :: SetDimensions(nscoord width, nscoord height)
     nsIPresContext  *px = mViewManager->GetPresContext();
     float           t2p = px->GetTwipsToPixels();
   
-    mWindow->Resize(NS_TO_INT_ROUND(t2p * width), NS_TO_INT_ROUND(t2p * height),
+    mWindow->Resize(NSTwipsToIntPixels(width, t2p), NSTwipsToIntPixels(height, t2p),
                     PR_TRUE);
 
     NS_RELEASE(px);
diff --git a/mozilla/view/src/nsViewManager.cpp b/mozilla/view/src/nsViewManager.cpp
index 267d158c6bc..3afd67adc01 100644
--- a/mozilla/view/src/nsViewManager.cpp
+++ b/mozilla/view/src/nsViewManager.cpp
@@ -324,15 +324,15 @@ void nsViewManager :: Refresh(nsIView *aView, nsIRenderingContext *aContext, nsI
 
   GetWindowOffsets(&xoff, &yoff);
 
-  region->Offset(NS_TO_INT_ROUND(-xoff * scale), NS_TO_INT_ROUND(-yoff * scale));
+  region->Offset(NSTwipsToIntPixels(-xoff, scale), NSTwipsToIntPixels(-yoff, scale));
 //  localcx->SetClipRegion(*region, nsClipCombine_kIntersect);
   localcx->SetClipRegion(*region, nsClipCombine_kReplace);
-  region->Offset(NS_TO_INT_ROUND(xoff * scale), NS_TO_INT_ROUND(yoff * scale));
+  region->Offset(NSTwipsToIntPixels(xoff, scale), NSTwipsToIntPixels(yoff, scale));
 
   nsRect trect;
 
   region->GetBoundingBox(&trect.x, &trect.y, &trect.width, &trect.height);
-  trect *= mContext->GetPixelsToTwips();
+  trect.ScaleRoundOut(mContext->GetPixelsToTwips());
 
   aView->Paint(*localcx, trect, 0);
 
@@ -439,7 +439,7 @@ void nsViewManager :: Refresh(nsIView *aView, nsIRenderingContext *aContext, nsR
   {
     nsRect pixrect = trect;
 
-    pixrect *= mContext->GetTwipsToPixels();
+    pixrect.ScaleRoundIn(mContext->GetTwipsToPixels());
     mDirtyRegion->Subtract(pixrect.x, pixrect.y, pixrect.width, pixrect.height);
   }
 
@@ -553,7 +553,7 @@ void nsViewManager :: UpdateView(nsIView *aView, const nsRect &aRect, PRUint32 a
         rrect = mDirtyRect;
 #else
         mDirtyRegion->GetBoundingBox(&rrect.x, &rrect.y, &rrect.width, &rrect.height);
-        rrect *= mContext->GetPixelsToTwips();
+        rrect.ScaleRoundOut(mContext->GetPixelsToTwips());
 #endif
         rrect.IntersectRect(rrect, vrect);
 
@@ -1040,7 +1040,7 @@ void nsViewManager :: AddRectToDirtyRegion(nsRect &aRect)
 
   nsRect  trect = aRect;
 
-  trect *= mContext->GetTwipsToPixels();
+  trect.ScaleRoundOut(mContext->GetTwipsToPixels());
   mDirtyRegion->Union(trect.x, trect.y, trect.width, trect.height);
 }
 
diff --git a/mozilla/webshell/src/nsDocumentViewer.cpp b/mozilla/webshell/src/nsDocumentViewer.cpp
index a8ca5bfbd62..2a2d619bd9c 100644
--- a/mozilla/webshell/src/nsDocumentViewer.cpp
+++ b/mozilla/webshell/src/nsDocumentViewer.cpp
@@ -349,8 +349,8 @@ DocumentViewerImpl::Init(nsNativeWidget aNativeParent,
     mWindow->GetBounds(bounds);
     width = bounds.width;
     height = bounds.height;
-    width = NS_TO_INT_ROUND(width * mPresContext->GetPixelsToTwips());
-    height = NS_TO_INT_ROUND(height * mPresContext->GetPixelsToTwips());
+    width = NSIntPixelsToTwips(width, mPresContext->GetPixelsToTwips());
+    height = NSIntPixelsToTwips(height, mPresContext->GetPixelsToTwips());
     mViewManager->DisableRefresh();
     mViewManager->SetWindowDimensions(width, height);
 
diff --git a/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp b/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
index f899f7d1bae..097b16bd25e 100644
--- a/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
+++ b/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
@@ -535,7 +535,7 @@ nsBrowserWindow::CreateToolBar(PRInt32 aWidth)
   float t2d = dc->GetTwipsToDevUnits();
   nsFont font(TOOL_BAR_FONT, NS_FONT_STYLE_NORMAL, NS_FONT_VARIANT_NORMAL,
               NS_FONT_WEIGHT_NORMAL, 0,
-              nscoord(t2d * NS_POINTS_TO_TWIPS_INT(TOOL_BAR_FONT_SIZE)));
+              nscoord(t2d * NSIntPointsToTwips(TOOL_BAR_FONT_SIZE)));
   NS_RELEASE(dc);
 
   // Create and place back button
@@ -601,7 +601,7 @@ nsBrowserWindow::CreateStatusBar(PRInt32 aWidth)
   float t2d = dc->GetTwipsToDevUnits();
   nsFont font(STATUS_BAR_FONT, NS_FONT_STYLE_NORMAL, NS_FONT_VARIANT_NORMAL,
               NS_FONT_WEIGHT_NORMAL, 0,
-              nscoord(t2d * NS_POINTS_TO_TWIPS_INT(STATUS_BAR_FONT_SIZE)));
+              nscoord(t2d * NSIntPointsToTwips(STATUS_BAR_FONT_SIZE)));
   NS_RELEASE(dc);
 
   nsRect r(0, 0, aWidth, THROBBER_HEIGHT);
diff --git a/mozilla/widget/src/mac/nsDeviceContextMac.cpp b/mozilla/widget/src/mac/nsDeviceContextMac.cpp
index eee1a17dc5d..2d041319d8a 100644
--- a/mozilla/widget/src/mac/nsDeviceContextMac.cpp
+++ b/mozilla/widget/src/mac/nsDeviceContextMac.cpp
@@ -109,7 +109,7 @@ nsresult nsDeviceContextMac :: Init(nsNativeWidget aNativeWidget)
   {
     mTwipsToPixels = (((float)::XDisplayWidth(XtDisplay((Widget)mNativeWidget), DefaultScreen(XtDisplay((Widget)mNativeWidget)))) /
   		    ((float)::XDisplayWidthMM(XtDisplay((Widget)mNativeWidget),DefaultScreen(XtDisplay((Widget)mNativeWidget)) )) * 25.4) / 
-      NS_POINTS_TO_TWIPS_FLOAT(72.0f);
+      (float)NSIntPointsToTwips(72);
     
     mPixelsToTwips = 1.0f / mTwipsToPixels;
   }*/
diff --git a/mozilla/widget/src/windows/nsScrollbar.cpp b/mozilla/widget/src/windows/nsScrollbar.cpp
index 4f735f414c3..6c83c2cc21f 100644
--- a/mozilla/widget/src/windows/nsScrollbar.cpp
+++ b/mozilla/widget/src/windows/nsScrollbar.cpp
@@ -30,7 +30,7 @@
 nsScrollbar::nsScrollbar(nsISupports *aOuter, PRBool aIsVertical) : nsWindow(aOuter)
 {
     mPositionFlag  = (aIsVertical) ? SBS_VERT : SBS_HORZ;
-    mScaleFactor   = 1.0;
+    mScaleFactor   = 1.0f;
     mLineIncrement = 0;
     mBackground    = ::GetSysColor(COLOR_SCROLLBAR);
     mBrush         = ::CreateSolidBrush(NSRGB_2_COLOREF(mBackground));
@@ -75,9 +75,9 @@ nsresult nsScrollbar::QueryObject(const nsIID& aIID, void** aInstancePtr)
 void nsScrollbar::SetMaxRange(PRUint32 aEndRange)
 {
     if (aEndRange > 32767)
-        mScaleFactor = aEndRange / 32767.0;
+        mScaleFactor = aEndRange / 32767.0f;
     if (mWnd) {
-        VERIFY(::SetScrollRange(mWnd, SB_CTL, 0, NS_TO_INT_ROUND(aEndRange / mScaleFactor), TRUE));
+        VERIFY(::SetScrollRange(mWnd, SB_CTL, 0, NSToIntRound(aEndRange / mScaleFactor), TRUE));
     }
 }
 
@@ -94,7 +94,7 @@ PRUint32 nsScrollbar::GetMaxRange()
         VERIFY(::GetScrollRange(mWnd, SB_CTL, &startRange, &endRange));
     }
 
-    return (PRUint32)NS_TO_INT_ROUND(endRange * mScaleFactor);
+    return (PRUint32)NSToIntRound(endRange * mScaleFactor);
 }
 
 
@@ -105,7 +105,7 @@ PRUint32 nsScrollbar::GetMaxRange()
 //-------------------------------------------------------------------------
 void nsScrollbar::SetPosition(PRUint32 aPos)
 {
-    ::SetScrollPos(mWnd, SB_CTL, NS_TO_INT_ROUND(aPos / mScaleFactor), TRUE);
+    ::SetScrollPos(mWnd, SB_CTL, NSToIntRound(aPos / mScaleFactor), TRUE);
 }
 
 
@@ -116,7 +116,7 @@ void nsScrollbar::SetPosition(PRUint32 aPos)
 //-------------------------------------------------------------------------
 PRUint32 nsScrollbar::GetPosition()
 {
-    return (PRUint32)NS_TO_INT_ROUND(::GetScrollPos(mWnd, SB_CTL) * mScaleFactor);
+    return (PRUint32)NSToIntRound(::GetScrollPos(mWnd, SB_CTL) * mScaleFactor);
 }
 
 
@@ -131,7 +131,7 @@ void nsScrollbar::SetThumbSize(PRUint32 aSize)
         SCROLLINFO si;
         si.cbSize = sizeof(SCROLLINFO);
         si.fMask = SIF_PAGE;
-        si.nPage = NS_TO_INT_ROUND(aSize / mScaleFactor);
+        si.nPage = NSToIntRound(aSize / mScaleFactor);
         ::SetScrollInfo(mWnd, SB_CTL, &si, TRUE);
     }
 }
@@ -149,7 +149,7 @@ PRUint32 nsScrollbar::GetThumbSize()
         si.cbSize = sizeof(SCROLLINFO);
         si.fMask = SIF_PAGE;
         VERIFY(::GetScrollInfo(mWnd, SB_CTL, &si));
-        return (PRUint32)NS_TO_INT_ROUND(si.nPage * mScaleFactor);
+        return (PRUint32)NSToIntRound(si.nPage * mScaleFactor);
     }
 
     return 0;
@@ -163,7 +163,7 @@ PRUint32 nsScrollbar::GetThumbSize()
 //-------------------------------------------------------------------------
 void nsScrollbar::SetLineIncrement(PRUint32 aSize)
 {
-    mLineIncrement = NS_TO_INT_ROUND(aSize / mScaleFactor);
+    mLineIncrement = NSToIntRound(aSize / mScaleFactor);
 }
 
 
@@ -174,7 +174,7 @@ void nsScrollbar::SetLineIncrement(PRUint32 aSize)
 //-------------------------------------------------------------------------
 PRUint32 nsScrollbar::GetLineIncrement()
 {
-    return (PRUint32)NS_TO_INT_ROUND(mLineIncrement * mScaleFactor);
+    return (PRUint32)NSToIntRound(mLineIncrement * mScaleFactor);
 }
 
 
@@ -187,20 +187,20 @@ void nsScrollbar::SetParameters(PRUint32 aMaxRange, PRUint32 aThumbSize,
                                 PRUint32 aPosition, PRUint32 aLineIncrement)
 {
     if (aMaxRange > 32767)
-        mScaleFactor = aMaxRange / 32767.0;
+        mScaleFactor = aMaxRange / 32767.0f;
 
     if (mWnd) {
         SCROLLINFO si;
         si.cbSize = sizeof(SCROLLINFO);
         si.fMask = SIF_PAGE | SIF_POS | SIF_RANGE;
-        si.nPage = NS_TO_INT_ROUND(aThumbSize / mScaleFactor);
-        si.nPos = NS_TO_INT_ROUND(aPosition / mScaleFactor);
+        si.nPage = NSToIntRound(aThumbSize / mScaleFactor);
+        si.nPos = NSToIntRound(aPosition / mScaleFactor);
         si.nMin = 0;
-        si.nMax = NS_TO_INT_ROUND(aMaxRange / mScaleFactor);
+        si.nMax = NSToIntRound(aMaxRange / mScaleFactor);
         ::SetScrollInfo(mWnd, SB_CTL, &si, TRUE);
     }
 
-    mLineIncrement = NS_TO_INT_ROUND(aLineIncrement / mScaleFactor);
+    mLineIncrement = NSToIntRound(aLineIncrement / mScaleFactor);
 }
 
 
@@ -257,10 +257,10 @@ PRBool nsScrollbar::OnScroll(UINT scrollCode, int cPos)
                 event.point.x = cpos.x;
                 event.point.y = cpos.y;
                 event.time = ::GetMessageTime();
-                event.position = (PRUint32)NS_TO_INT_ROUND(newPosition * mScaleFactor);
+                event.position = (PRUint32)NSToIntRound(newPosition * mScaleFactor);
 
                 result = ConvertStatus((*mEventCallback)(&event));
-                newPosition = NS_TO_INT_ROUND(event.position / mScaleFactor);
+                newPosition = NSToIntRound(event.position / mScaleFactor);
             }
 
             ::SetScrollPos(mWnd, SB_CTL, newPosition, TRUE);
@@ -291,10 +291,10 @@ PRBool nsScrollbar::OnScroll(UINT scrollCode, int cPos)
                 event.point.x = cpos.x;
                 event.point.y = cpos.y;
                 event.time = ::GetMessageTime();
-                event.position = (PRUint32)NS_TO_INT_ROUND(newPosition * mScaleFactor);
+                event.position = (PRUint32)NSToIntRound(newPosition * mScaleFactor);
 
                 result = ConvertStatus((*mEventCallback)(&event));
-                newPosition = NS_TO_INT_ROUND(event.position / mScaleFactor);
+                newPosition = NSToIntRound(event.position / mScaleFactor);
             }
 
             ::SetScrollPos(mWnd, SB_CTL, newPosition, TRUE);
@@ -330,11 +330,11 @@ PRBool nsScrollbar::OnScroll(UINT scrollCode, int cPos)
                 event.point.x = cpos.x;
                 event.point.y = cpos.y;
                 event.time = ::GetMessageTime();
-                event.position = (PRUint32)NS_TO_INT_ROUND(newPosition * mScaleFactor);;
+                event.position = (PRUint32)NSToIntRound(newPosition * mScaleFactor);;
 
 
                 result = ConvertStatus((*mEventCallback)(&event));
-                newPosition = NS_TO_INT_ROUND(event.position / mScaleFactor);
+                newPosition = NSToIntRound(event.position / mScaleFactor);
             }
 
             ::SetScrollPos(mWnd, SB_CTL, newPosition, TRUE);
@@ -369,10 +369,10 @@ PRBool nsScrollbar::OnScroll(UINT scrollCode, int cPos)
                 event.point.x = cpos.x;
                 event.point.y = cpos.y;
                 event.time = ::GetMessageTime();
-                event.position = (PRUint32)NS_TO_INT_ROUND(newPosition * mScaleFactor);
+                event.position = (PRUint32)NSToIntRound(newPosition * mScaleFactor);
 
                 result = ConvertStatus((*mEventCallback)(&event));
-                newPosition = NS_TO_INT_ROUND(event.position / mScaleFactor);
+                newPosition = NSToIntRound(event.position / mScaleFactor);
             }
 
             ::SetScrollPos(mWnd, SB_CTL, newPosition - 10, TRUE);
@@ -401,10 +401,10 @@ PRBool nsScrollbar::OnScroll(UINT scrollCode, int cPos)
                 event.point.x = cpos.x;
                 event.point.y = cpos.y;
                 event.time = ::GetMessageTime();
-                event.position = (PRUint32)NS_TO_INT_ROUND(newPosition * mScaleFactor);
+                event.position = (PRUint32)NSToIntRound(newPosition * mScaleFactor);
 
                 result = ConvertStatus((*mEventCallback)(&event));
-                newPosition = NS_TO_INT_ROUND(event.position * mScaleFactor);
+                newPosition = NSToIntRound(event.position * mScaleFactor);
             }
 
             ::SetScrollPos(mWnd, SB_CTL, newPosition, TRUE);
diff --git a/mozilla/widget/src/windows/nsScrollbar.h b/mozilla/widget/src/windows/nsScrollbar.h
index 894030c3bca..a76ae56732f 100644
--- a/mozilla/widget/src/windows/nsScrollbar.h
+++ b/mozilla/widget/src/windows/nsScrollbar.h
@@ -72,7 +72,7 @@ protected:
 private:
     DWORD   mPositionFlag;
     int     mLineIncrement;
-    double  mScaleFactor;
+    float   mScaleFactor;
 };
 
 #endif // nsButton_h__