void ConvertToParentCoords(nscoord* aX, nscoord* aY) { *aX += mPosX; *aY += mPosY; }
void ConvertToParentCoords(nscoord* aX, nscoord* aY) const { *aX += mPosX; *aY += mPosY; }
  void ConvertToParentCoords(nscoord* aX, nscoord* aY) { *aX += mPosX; *aY += mPosY; }