Bug 485121. The screen coordinates for an element should be snapped to the nearest screen pixel, not rounded out, for consistency with the way we position native widgets and snap rectangle drawing. r=dbaron

--HG--
extra : rebase_source : d76f8fa9b8b9096ad833708a913e9af05b22dcea

layout/generic/nsFrame.cpp

@@ -3600,7 +3600,7 @@ nsIntRect nsIFrame::GetScreenRectExternal() const
 
 nsIntRect nsIFrame::GetScreenRect() const
 {
-  return nsRect::ToOutsidePixels(GetScreenRectInAppUnits(), PresContext()->AppUnitsPerDevPixel());
+  return nsRect::ToNearestPixels(GetScreenRectInAppUnits(), PresContext()->AppUnitsPerDevPixel());
 }
 
 // virtual