diff --git a/mozilla/docshell/base/nsWebShell.cpp b/mozilla/docshell/base/nsWebShell.cpp
index 85ce19dc707..5316c36c620 100644
--- a/mozilla/docshell/base/nsWebShell.cpp
+++ b/mozilla/docshell/base/nsWebShell.cpp
@@ -563,8 +563,12 @@ nsWebShell::Init(nsNativeWidget aNativeParent,
     goto done;
   }
   mDeviceContext->Init(aNativeParent);
-  mDeviceContext->SetDevUnitsToAppUnits(mDeviceContext->GetDevUnitsToTwips());
-  mDeviceContext->SetAppUnitsToDevUnits(mDeviceContext->GetTwipsToDevUnits());
+  float dev2twip;
+  mDeviceContext->GetDevUnitsToTwips(dev2twip);
+  mDeviceContext->SetDevUnitsToAppUnits(dev2twip);
+  float twip2dev;
+  mDeviceContext->GetTwipsToDevUnits(twip2dev);
+  mDeviceContext->SetAppUnitsToDevUnits(twip2dev);
 //  mDeviceContext->SetGamma(1.7f);
   mDeviceContext->SetGamma(1.0f);
 
diff --git a/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp b/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp
index 6e635e8d473..7136b2a7479 100644
--- a/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp
+++ b/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp
@@ -66,7 +66,7 @@ NS_IMPL_QUERY_INTERFACE(nsDeviceContextUnix, kDeviceContextIID)
 NS_IMPL_ADDREF(nsDeviceContextUnix)
 NS_IMPL_RELEASE(nsDeviceContextUnix)
 
-nsresult nsDeviceContextUnix :: Init(nsNativeWidget aNativeWidget)
+NS_IMETHODIMP nsDeviceContextUnix :: Init(nsNativeWidget aNativeWidget)
 {
   NS_ASSERTION(!(aNativeWidget == nsnull), "attempt to init devicecontext with null widget");
 
@@ -91,16 +91,18 @@ nsresult nsDeviceContextUnix :: Init(nsNativeWidget aNativeWidget)
 }
 
 
-float nsDeviceContextUnix :: GetScrollBarWidth() const
+NS_IMETHODIMP nsDeviceContextUnix :: GetScrollBarWidth(float &aWidth) const
 {
   // XXX Should we push this to widget library
-  return 240.0;
+  aWidth = 240.0;
+  return NS_OK;
 }
 
-float nsDeviceContextUnix :: GetScrollBarHeight() const
+NS_IMETHODIMP nsDeviceContextUnix :: GetScrollBarHeight(float &aHeight) const
 {
   // XXX Should we push this to widget library
-  return 240.0;
+  aHeight = 240.0;
+  return NS_OK;
 }
 
 
diff --git a/mozilla/gfx/src/motif/nsDeviceContextUnix.h b/mozilla/gfx/src/motif/nsDeviceContextUnix.h
index 333e4a1db52..e81861ab09b 100644
--- a/mozilla/gfx/src/motif/nsDeviceContextUnix.h
+++ b/mozilla/gfx/src/motif/nsDeviceContextUnix.h
@@ -65,10 +65,10 @@ public:
 
 //  NS_IMETHOD CreateILColorSpace(IL_ColorSpace*& aColorSpace);
 
-  virtual nsresult Init(nsNativeWidget aNativeWidget);
+  NS_IMETHOD  Init(nsNativeWidget aNativeWidget);
 
-  virtual float GetScrollBarWidth() const;
-  virtual float GetScrollBarHeight() const;
+  NS_IMETHOD  GetScrollBarWidth(float &aWidth) const;
+  NS_IMETHOD  GetScrollBarHeight(float &aHeight) const;
 
   virtual nsDrawingSurface GetDrawingSurface(nsIRenderingContext &aContext);
 
diff --git a/mozilla/gfx/src/nsDeviceContext.cpp b/mozilla/gfx/src/nsDeviceContext.cpp
index a0754a151c7..63a65cc647f 100644
--- a/mozilla/gfx/src/nsDeviceContext.cpp
+++ b/mozilla/gfx/src/nsDeviceContext.cpp
@@ -83,7 +83,7 @@ DeviceContextImpl :: ~DeviceContextImpl()
   }
 }
 
-nsresult DeviceContextImpl :: Init(nsNativeWidget aWidget)
+NS_IMETHODIMP DeviceContextImpl :: Init(nsNativeWidget aWidget)
 {
   for (PRInt32 cnt = 0; cnt < 256; cnt++)
     mGammaTable[cnt] = cnt;
@@ -93,14 +93,16 @@ nsresult DeviceContextImpl :: Init(nsNativeWidget aWidget)
   return NS_OK;
 }
 
-float DeviceContextImpl :: GetTwipsToDevUnits() const
+NS_IMETHODIMP DeviceContextImpl :: GetTwipsToDevUnits(float &aTwipsToDevUnits) const
 {
-  return mTwipsToPixels;
+  aTwipsToDevUnits = mTwipsToPixels;
+  return NS_OK;
 }
 
-float DeviceContextImpl :: GetDevUnitsToTwips() const
+NS_IMETHODIMP DeviceContextImpl :: GetDevUnitsToTwips(float &aDevUnitsToTwips) const
 {
-  return mPixelsToTwips;
+  aDevUnitsToTwips = mPixelsToTwips;
+  return NS_OK;
 }
 
 void DeviceContextImpl :: SetAppUnitsToDevUnits(float aAppUnits)
@@ -123,15 +125,16 @@ float DeviceContextImpl :: GetDevUnitsToAppUnits() const
   return mDevUnitsToAppUnits;
 }
 
-nsIRenderingContext * DeviceContextImpl :: CreateRenderingContext(nsIView *aView)
+NS_IMETHODIMP DeviceContextImpl :: CreateRenderingContext(nsIView *aView, nsIRenderingContext *&aContext)
 {
-  nsIRenderingContext *pContext = nsnull;
+  nsIRenderingContext *pContext;
   nsIWidget           *win = aView->GetWidget();
-  nsresult            rv;
+  nsresult             rv;
 
   static NS_DEFINE_IID(kRCCID, NS_RENDERING_CONTEXT_CID);
   static NS_DEFINE_IID(kRCIID, NS_IRENDERING_CONTEXT_IID);
 
+  aContext = nsnull;
   rv = NSRepository::CreateInstance(kRCCID, nsnull, kRCIID, (void **)&pContext);
 
   if (NS_OK == rv) {
@@ -142,10 +145,11 @@ nsIRenderingContext * DeviceContextImpl :: CreateRenderingContext(nsIView *aView
   }
 
   NS_IF_RELEASE(win);
-  return pContext;
+  aContext = pContext;
+  return rv;
 }
 
-nsresult DeviceContextImpl :: InitRenderingContext(nsIRenderingContext *aContext, nsIWidget *aWin)
+NS_IMETHODIMP DeviceContextImpl :: InitRenderingContext(nsIRenderingContext *aContext, nsIWidget *aWin)
 {
   return (aContext->Init(this, aWin));
 }
diff --git a/mozilla/gfx/src/nsDeviceContext.h b/mozilla/gfx/src/nsDeviceContext.h
index d217992124c..455e908679b 100644
--- a/mozilla/gfx/src/nsDeviceContext.h
+++ b/mozilla/gfx/src/nsDeviceContext.h
@@ -32,13 +32,13 @@ public:
 
   NS_DECL_ISUPPORTS
 
-  virtual nsresult Init(nsNativeWidget aWidget);
+  NS_IMETHOD  Init(nsNativeWidget aWidget);
 
-  virtual nsIRenderingContext * CreateRenderingContext(nsIView *aView);
-  virtual nsresult InitRenderingContext(nsIRenderingContext *aContext, nsIWidget *aWindow);
+  NS_IMETHOD  CreateRenderingContext(nsIView *aView, nsIRenderingContext *&aContext);
+  NS_IMETHOD  InitRenderingContext(nsIRenderingContext *aContext, nsIWidget *aWindow);
 
-  virtual float GetDevUnitsToTwips() const;
-  virtual float GetTwipsToDevUnits() const;
+  NS_IMETHOD  GetDevUnitsToTwips(float &aDevUnitsToTwips) const;
+  NS_IMETHOD  GetTwipsToDevUnits(float &aTwipsToDevUnits) const;
 
   virtual void SetAppUnitsToDevUnits(float aAppUnits);
   virtual void SetDevUnitsToAppUnits(float aDevUnits);
diff --git a/mozilla/gfx/src/nsIDeviceContext.h b/mozilla/gfx/src/nsIDeviceContext.h
index a8207c20058..34dcdf7e10c 100644
--- a/mozilla/gfx/src/nsIDeviceContext.h
+++ b/mozilla/gfx/src/nsIDeviceContext.h
@@ -66,15 +66,15 @@ typedef NI_ColorSpace IL_ColorSpace;
 class nsIDeviceContext : public nsISupports
 {
 public:
-  virtual nsresult Init(nsNativeWidget aWidget) = 0;
+  NS_IMETHOD  Init(nsNativeWidget aWidget) = 0;
 
-  virtual nsIRenderingContext * CreateRenderingContext(nsIView *aView) = 0;
-  virtual nsresult InitRenderingContext(nsIRenderingContext *aContext, nsIWidget *aWindow) = 0;
+  NS_IMETHOD  CreateRenderingContext(nsIView *aView, nsIRenderingContext *&aContext) = 0;
+  NS_IMETHOD  InitRenderingContext(nsIRenderingContext *aContext, nsIWidget *aWindow) = 0;
 
   //these are queries to figure out how large an output unit
   //(i.e. pixel) is in terms of twips (1/20 of a point)
-  virtual float GetDevUnitsToTwips() const = 0;
-  virtual float GetTwipsToDevUnits() const = 0;
+  NS_IMETHOD  GetDevUnitsToTwips(float &aDevUnitsToTwips) const = 0;
+  NS_IMETHOD  GetTwipsToDevUnits(float &aTwipsToDevUnits) const = 0;
 
   //these are set by the object that created this
   //device context to define what the scale is
@@ -88,8 +88,8 @@ public:
   virtual float GetAppUnitsToDevUnits() const = 0;
   virtual float GetDevUnitsToAppUnits() const = 0;
 
-  virtual float GetScrollBarWidth() const = 0;
-  virtual float GetScrollBarHeight() const = 0;
+  NS_IMETHOD  GetScrollBarWidth(float &aWidth) const = 0;
+  NS_IMETHOD  GetScrollBarHeight(float &aHeight) const = 0;
 
   //be sure to Relase() after you are done with the Get()
   virtual nsIFontCache * GetFontCache() = 0;
diff --git a/mozilla/gfx/src/windows/nsDeviceContextWin.cpp b/mozilla/gfx/src/windows/nsDeviceContextWin.cpp
index 72341fa87e1..6465118b9c8 100644
--- a/mozilla/gfx/src/windows/nsDeviceContextWin.cpp
+++ b/mozilla/gfx/src/windows/nsDeviceContextWin.cpp
@@ -52,7 +52,7 @@ nsDeviceContextWin :: ~nsDeviceContextWin()
   }
 }
 
-nsresult nsDeviceContextWin::Init(nsNativeWidget aWidget)
+NS_IMETHODIMP nsDeviceContextWin::Init(nsNativeWidget aWidget)
 {
   HWND  hwnd = (HWND)aWidget;
   HDC   hdc = ::GetDC(hwnd);
@@ -67,14 +67,16 @@ nsresult nsDeviceContextWin::Init(nsNativeWidget aWidget)
   return DeviceContextImpl::Init(aWidget);
 }
 
-float nsDeviceContextWin :: GetScrollBarWidth() const
+NS_IMETHODIMP nsDeviceContextWin :: GetScrollBarWidth(float &aWidth) const
 {
-  return ::GetSystemMetrics(SM_CXVSCROLL) * mDevUnitsToAppUnits;
+  aWidth = ::GetSystemMetrics(SM_CXVSCROLL) * mDevUnitsToAppUnits;
+  return NS_OK;
 }
 
-float nsDeviceContextWin :: GetScrollBarHeight() const
+NS_IMETHODIMP nsDeviceContextWin :: GetScrollBarHeight(float &aHeight) const
 {
-  return ::GetSystemMetrics(SM_CXHSCROLL) * mDevUnitsToAppUnits;
+  aHeight = ::GetSystemMetrics(SM_CXHSCROLL) * mDevUnitsToAppUnits;
+  return NS_OK;
 }
 
 nsDrawingSurface nsDeviceContextWin :: GetDrawingSurface(nsIRenderingContext &aContext)
diff --git a/mozilla/gfx/src/windows/nsDeviceContextWin.h b/mozilla/gfx/src/windows/nsDeviceContextWin.h
index bba73d8856f..0a6ee3b8819 100644
--- a/mozilla/gfx/src/windows/nsDeviceContextWin.h
+++ b/mozilla/gfx/src/windows/nsDeviceContextWin.h
@@ -27,10 +27,10 @@ class nsDeviceContextWin : public DeviceContextImpl
 public:
   nsDeviceContextWin();
 
-  virtual nsresult Init(nsNativeWidget aWidget);
+  NS_IMETHOD    Init(nsNativeWidget aWidget);
 
-  virtual float GetScrollBarWidth() const;
-  virtual float GetScrollBarHeight() const;
+  NS_IMETHOD    GetScrollBarWidth(float &aWidth) const;
+  NS_IMETHOD    GetScrollBarHeight(float &aHeight) const;
 
   //get a low level drawing surface for rendering. the rendering context
   //that is passed in is used to create the drawing surface if there isn't
diff --git a/mozilla/gfx/src/windows/nsFontMetricsWin.cpp b/mozilla/gfx/src/windows/nsFontMetricsWin.cpp
index 121b322b011..6002df4d5a8 100644
--- a/mozilla/gfx/src/windows/nsFontMetricsWin.cpp
+++ b/mozilla/gfx/src/windows/nsFontMetricsWin.cpp
@@ -175,7 +175,9 @@ void nsFontMetricsWin::RealizeFont(nsIDeviceContext *aContext)
   logFont.lfItalic = (mFont->style & NS_FONT_STYLE_ITALIC)
     ? TRUE : FALSE;
   float app2dev = aContext->GetAppUnitsToDevUnits();
-  float app2twip = app2dev * aContext->GetDevUnitsToTwips();
+  float app2twip;
+  aContext->GetDevUnitsToTwips(app2twip);
+  app2twip *= app2dev;
 
   float rounded = ((float)NSIntPointsToTwips(NSTwipsToFloorIntPoints(nscoord(mFont->size * app2twip)))) / app2twip;
     // round font size off to floor point size to be windows compatible
@@ -280,11 +282,13 @@ nscoord nsFontMetricsWin :: GetWidth(nsIDeviceContext *aContext, const nsString&
 
 
   float app2dev = aContext->GetAppUnitsToDevUnits();
-  float app2twip = app2dev * aContext->GetDevUnitsToTwips();
+  float dev2twip;
+  aContext->GetDevUnitsToTwips(dev2twip);
+  float app2twip = dev2twip * app2dev;
   //printf("[%s] %d  %d = %d\n", str, size.cx, nscoord(((float)size.cx)*aContext->GetDevUnitsToTwips()), GetWidth(str));
 
   delete[] str;
-  return nscoord(((float)size.cx)*aContext->GetDevUnitsToTwips());
+  return nscoord(float(size.cx) * dev2twip);
 }
 
 nscoord nsFontMetricsWin :: GetWidth(const PRUnichar *aString, PRUint32 aLength)
diff --git a/mozilla/layout/base/src/nsPrintPreviewContext.cpp b/mozilla/layout/base/src/nsPrintPreviewContext.cpp
index 0ed1467b0d5..74a59856b2b 100644
--- a/mozilla/layout/base/src/nsPrintPreviewContext.cpp
+++ b/mozilla/layout/base/src/nsPrintPreviewContext.cpp
@@ -55,7 +55,9 @@ nscoord PrintPreviewContext::GetPageWidth()
 #else
   // For testing purposes make the page width smaller than the visible
   // area
-  nscoord sbar = NSToCoordRound(mDeviceContext->GetScrollBarWidth());
+  float sbWidth;
+  mDeviceContext->GetScrollBarWidth(sbWidth);
+  nscoord sbar = NSToCoordRound(sbWidth);
   return mVisibleArea.width - sbar - 2*100;
 #endif
 }
diff --git a/mozilla/layout/html/base/src/nsBodyFrame.cpp b/mozilla/layout/html/base/src/nsBodyFrame.cpp
index 6cf60b36dde..9e80c5f5548 100644
--- a/mozilla/layout/html/base/src/nsBodyFrame.cpp
+++ b/mozilla/layout/html/base/src/nsBodyFrame.cpp
@@ -498,7 +498,10 @@ nsSize nsBodyFrame::GetColumnAvailSpace(nsIPresContext*  aPresContext,
                       aBorderPadding.right;
       if (! aPresContext->IsPaginated()) {
         nsIDeviceContext* dc = aPresContext->GetDeviceContext();
-        result.width -= NSToCoordRound(dc->GetScrollBarWidth());
+        float             sbWidth;
+
+        dc->GetScrollBarWidth(sbWidth);
+        result.width -= NSToCoordRound(sbWidth);
         NS_RELEASE(dc);
       }
     }
diff --git a/mozilla/layout/html/base/src/nsRootPart.cpp b/mozilla/layout/html/base/src/nsRootPart.cpp
index addba8127b8..350176f1406 100644
--- a/mozilla/layout/html/base/src/nsRootPart.cpp
+++ b/mozilla/layout/html/base/src/nsRootPart.cpp
@@ -353,8 +353,10 @@ NS_METHOD RootContentFrame::Reflow(nsIPresContext&      aPresContext,
         nsSize          pageSize(aPresContext.GetPageWidth(),
                                  aPresContext.GetPageHeight());
         nsIDeviceContext *dx = aPresContext.GetDeviceContext();
+        float             sbWidth;
+        dx->GetScrollBarWidth(sbWidth);
         PRInt32 extra = aReflowState.maxSize.width - PAGE_SPACING_TWIPS*2 -
-          pageSize.width - NSToCoordRound(dx->GetScrollBarWidth());
+          pageSize.width - NSToCoordRound(sbWidth);
         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 25c71bfea9c..3a4720dc83d 100644
--- a/mozilla/layout/html/base/src/nsScrollFrame.cpp
+++ b/mozilla/layout/html/base/src/nsScrollFrame.cpp
@@ -167,8 +167,10 @@ 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();
+          float             sbWidth;
+          dx->GetScrollBarWidth(sbWidth);
           nscoord extra = aReflowState.maxSize.width - kidSize.width -
-                          NSToCoordRound(dx->GetScrollBarWidth());
+                          NSToCoordRound(sbWidth);
           NS_RELEASE(dx);
           nscoord         x = extra > 0 ? extra / 2 : 0;
 
@@ -378,8 +380,9 @@ nsScrollInnerFrame::Reflow(nsIPresContext&      aPresContext,
   // scroll bar width), and as high as it wants to be.
   nsSize        maxSize;
   nsIDeviceContext* dc = aPresContext.GetDeviceContext();
-  maxSize.width = aReflowState.maxSize.width -
-    NSToCoordRound(dc->GetScrollBarWidth());
+  float             sbWidth;
+  dc->GetScrollBarWidth(sbWidth);
+  maxSize.width = aReflowState.maxSize.width - NSToCoordRound(sbWidth);
   NS_RELEASE(dc);
   maxSize.height = NS_UNCONSTRAINEDSIZE;
   
diff --git a/mozilla/view/src/nsScrollingView.cpp b/mozilla/view/src/nsScrollingView.cpp
index 5de22c3ac61..c1fc286c1c4 100644
--- a/mozilla/view/src/nsScrollingView.cpp
+++ b/mozilla/view/src/nsScrollingView.cpp
@@ -406,10 +406,13 @@ nsresult nsScrollingView :: Init(nsIViewManager* aManager,
     if (nsnull != mCornerView)
     {
       nsRect trect;
+      float  sbWidth, sbHeight;
 
-      trect.width = NSToCoordRound(dx->GetScrollBarWidth());
+      dx->GetScrollBarWidth(sbWidth);
+      dx->GetScrollBarHeight(sbHeight);
+      trect.width = NSToCoordRound(sbWidth);
       trect.x = aBounds.x + aBounds.XMost() - trect.width;
-      trect.height = NSToCoordRound(dx->GetScrollBarHeight());
+      trect.height = NSToCoordRound(sbHeight);
       trect.y = aBounds.y + aBounds.YMost() - trect.height;
 
       rv = mCornerView->Init(mViewManager, trect, this, nsnull, nsnull, nsnull, -1, nsnull, 1.0f, nsViewVisibility_kHide);
@@ -423,11 +426,14 @@ nsresult nsScrollingView :: Init(nsIViewManager* aManager,
 
     if (nsnull != mVScrollBarView)
     {
-      nsRect trect = aBounds;
+      nsRect  trect = aBounds;
+      float   sbWidth, sbHeight;
 
-      trect.width = NSToCoordRound(dx->GetScrollBarWidth());
+      dx->GetScrollBarWidth(sbWidth);
+      dx->GetScrollBarHeight(sbHeight);
+      trect.width = NSToCoordRound(sbWidth);
       trect.x += aBounds.XMost() - trect.width;
-      trect.height -= NSToCoordRound(dx->GetScrollBarHeight());
+      trect.height -= NSToCoordRound(sbHeight);
 
       static NS_DEFINE_IID(kCScrollbarIID, NS_VERTSCROLLBAR_CID);
 
@@ -442,11 +448,14 @@ nsresult nsScrollingView :: Init(nsIViewManager* aManager,
 
     if (nsnull != mHScrollBarView)
     {
-      nsRect trect = aBounds;
+      nsRect  trect = aBounds;
+      float   sbWidth, sbHeight;
 
-      trect.height = NSToCoordRound(dx->GetScrollBarHeight());
+      dx->GetScrollBarWidth(sbWidth);
+      dx->GetScrollBarHeight(sbHeight);
+      trect.height = NSToCoordRound(sbHeight);
       trect.y += aBounds.YMost() - trect.height;
-      trect.width -= NSToCoordRound(dx->GetScrollBarWidth());
+      trect.width -= NSToCoordRound(sbWidth);
 
       static NS_DEFINE_IID(kCHScrollbarIID, NS_HORZSCROLLBAR_CID);
 
@@ -468,8 +477,11 @@ void nsScrollingView :: SetDimensions(nscoord width, nscoord height, PRBool aPai
   nsIPresContext    *cx = mViewManager->GetPresContext();
   nsIDeviceContext  *dx = cx->GetDeviceContext();
   nscoord           showHorz = 0, showVert = 0;
-  nscoord           scrollWidth = NSToCoordRound(dx->GetScrollBarWidth());
-  nscoord           scrollHeight = NSToCoordRound(dx->GetScrollBarHeight());
+  float             scrollWidthFloat, scrollHeightFloat;
+  dx->GetScrollBarWidth(scrollWidthFloat);
+  dx->GetScrollBarHeight(scrollHeightFloat);
+  nscoord           scrollWidth = NSToCoordRound(scrollWidthFloat);
+  nscoord           scrollHeight = NSToCoordRound(scrollHeightFloat);
 
   if (nsnull != mCornerView)
   {
diff --git a/mozilla/view/src/nsViewManager.cpp b/mozilla/view/src/nsViewManager.cpp
index 70128a04a2c..037d1c25fc7 100644
--- a/mozilla/view/src/nsViewManager.cpp
+++ b/mozilla/view/src/nsViewManager.cpp
@@ -1115,7 +1115,7 @@ nsIRenderingContext * nsViewManager :: CreateRenderingContext(nsIView &aView)
   if (nsnull != win)
   {
     dx = mContext->GetDeviceContext();
-    cx = dx->CreateRenderingContext(&aView);
+    dx->CreateRenderingContext(&aView, cx);
 
     if (nsnull != cx)
       cx->Translate(ax, ay);
diff --git a/mozilla/webshell/src/nsWebShell.cpp b/mozilla/webshell/src/nsWebShell.cpp
index 85ce19dc707..5316c36c620 100644
--- a/mozilla/webshell/src/nsWebShell.cpp
+++ b/mozilla/webshell/src/nsWebShell.cpp
@@ -563,8 +563,12 @@ nsWebShell::Init(nsNativeWidget aNativeParent,
     goto done;
   }
   mDeviceContext->Init(aNativeParent);
-  mDeviceContext->SetDevUnitsToAppUnits(mDeviceContext->GetDevUnitsToTwips());
-  mDeviceContext->SetAppUnitsToDevUnits(mDeviceContext->GetTwipsToDevUnits());
+  float dev2twip;
+  mDeviceContext->GetDevUnitsToTwips(dev2twip);
+  mDeviceContext->SetDevUnitsToAppUnits(dev2twip);
+  float twip2dev;
+  mDeviceContext->GetTwipsToDevUnits(twip2dev);
+  mDeviceContext->SetAppUnitsToDevUnits(twip2dev);
 //  mDeviceContext->SetGamma(1.7f);
   mDeviceContext->SetGamma(1.0f);
 
diff --git a/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp b/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
index ee306b762b9..2054fb163f5 100644
--- a/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
+++ b/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
@@ -605,7 +605,8 @@ nsBrowserWindow::CreateToolBar(PRInt32 aWidth)
   nsresult rv;
 
   nsIDeviceContext* dc = mWindow->GetDeviceContext();
-  float t2d = dc->GetTwipsToDevUnits();
+  float t2d;
+  dc->GetTwipsToDevUnits(t2d);
   nsFont font(TOOL_BAR_FONT, NS_FONT_STYLE_NORMAL, NS_FONT_VARIANT_NORMAL,
               NS_FONT_WEIGHT_NORMAL, 0,
               nscoord(t2d * NSIntPointsToTwips(TOOL_BAR_FONT_SIZE)));
@@ -671,7 +672,8 @@ nsBrowserWindow::CreateStatusBar(PRInt32 aWidth)
   nsresult rv;
 
   nsIDeviceContext* dc = mWindow->GetDeviceContext();
-  float t2d = dc->GetTwipsToDevUnits();
+  float t2d;
+  dc->GetTwipsToDevUnits(t2d);
   nsFont font(STATUS_BAR_FONT, NS_FONT_STYLE_NORMAL, NS_FONT_VARIANT_NORMAL,
               NS_FONT_WEIGHT_NORMAL, 0,
               nscoord(t2d * NSIntPointsToTwips(STATUS_BAR_FONT_SIZE)));