This test checks that changing the grid-definition-rows lead to a repaint. The final grid element should be 100px * 150px, the grid item should be 100px * 100px. No trace of the elements before the grid-definition-rows change should be seen.
(repaint rects
  (rect 8 48 100 50)
  (rect 8 48 100 100)
  (rect 8 48 100 150)
)