Part of fix for bug 359341 that somehow didn't make it in the first time. r+sr=roc

gfx/src/os2/nsImageOS2.cpp

@@ -366,9 +366,9 @@ nsImageOS2 :: Draw(nsIRenderingContext &aContext, nsIDrawingSurface* aSurface,
                        { aSX + aSWidth, mInfo->cy - aSY } };    // SUR
                        
    PRBool fPrinting = PR_FALSE;
-   nsIDeviceContext*  context;
-   aContext.GetDeviceContext(context);
-   if (((nsDeviceContextOS2 *)context)->mPrintDC) {
+   nsCOMPtr<nsIDeviceContext>  context;
+   aContext.GetDeviceContext(*getter_AddRefs(context));
+   if (((nsDeviceContextOS2 *)context.get())->mPrintDC) {
       fPrinting = PR_TRUE;
    }
 
@@ -738,9 +738,9 @@ NS_IMETHODIMP nsImageOS2::DrawTile(nsIRenderingContext &aContext,
    PRBool padded = (aPadX || aPadY);
 
    // Get the scale - if greater than 1 then do slow tile which
-   nsIDeviceContext *theDeviceContext;
+   nsCOMPtr<nsIDeviceContext> theDeviceContext;
    float scale;
-   aContext.GetDeviceContext(theDeviceContext);
+   aContext.GetDeviceContext(*getter_AddRefs(theDeviceContext));
    theDeviceContext->GetCanonicalPixelScale(scale);
 
    nsRect ValidRect (0, 0, ImageWidth, ImageHeight);

gfx/tests/coverage/nsCoverage.cpp

@@ -94,11 +94,10 @@ nsFont  *font;
 nsPoint *pointlist;
 
    // Get the size of a pixel.
-  nsIDeviceContext* deviceContext;
-  aSurface->GetDeviceContext(deviceContext);
+  nsCOMPtr<nsIDeviceContext> deviceContext;
+  aSurface->GetDeviceContext(*getter_AddRefs(deviceContext));
   float p2t; // pixel to twips conversion
   p2t = deviceContext->DevUnitsToAppUnits();
-  NS_RELEASE(deviceContext);
 
   font = new nsFont("Times", NS_FONT_STYLE_NORMAL,NS_FONT_VARIANT_NORMAL,NS_FONT_WEIGHT_BOLD,0,12);
   aSurface->SetFont(*font);

widget/src/xpwidgets/nsBaseWidget.cpp

@@ -653,7 +653,6 @@ nsIToolkit* nsBaseWidget::GetToolkit()
 //-------------------------------------------------------------------------
 nsIDeviceContext* nsBaseWidget::GetDeviceContext() 
 {
-  NS_IF_ADDREF(mContext);
   return mContext; 
 }