--- a/gfx/thebes/gfx2DGlue.h
+++ b/gfx/thebes/gfx2DGlue.h
@@ -46,21 +46,31 @@ inline gfxMatrix ThebesMatrix(const Matr
                    aMatrix._22, aMatrix._31, aMatrix._32);
 }
 
 inline Point ToPoint(const gfxPoint &aPoint)
 {
   return Point(Float(aPoint.x), Float(aPoint.y));
 }
 
+inline Size ToSize(const gfxSize &aSize)
+{
+  return Size(Float(aSize.width), Float(aSize.height));
+}
+
 inline gfxPoint ThebesPoint(const Point &aPoint)
 {
   return gfxPoint(aPoint.x, aPoint.y);
 }
 
+inline gfxSize ThebesSize(const Size &aSize)
+{
+  return gfxSize(aSize.width, aSize.height);
+}
+
 inline gfxRect ThebesRect(const Rect &aRect)
 {
   return gfxRect(aRect.x, aRect.y, aRect.width, aRect.height);
 }
 
 inline gfxRect ThebesRect(const RectDouble &aRect)
 {
   return gfxRect(aRect.x, aRect.y, aRect.width, aRect.height);