Revert of Don't always repaint on zIndex change

LayoutTests/compositing/repaint/should-not-repaint-composited-descendants-expected.txt

Index: LayoutTests/compositing/repaint/should-not-repaint-composited-descendants-expected.txt
diff --git a/LayoutTests/compositing/repaint/should-not-repaint-composited-descendants-expected.txt b/LayoutTests/compositing/repaint/should-not-repaint-composited-descendants-expected.txt
index 4b49deea93cdda613247716d44bf3ed442f0cb14..4d8bd15165986af087a41ff662be7ba6d48b5e5b 100644
--- a/LayoutTests/compositing/repaint/should-not-repaint-composited-descendants-expected.txt
+++ b/LayoutTests/compositing/repaint/should-not-repaint-composited-descendants-expected.txt
@@ -174,6 +174,11 @@ clip change with non-composited child
           (position 8.00 620.00)
           (bounds 100.00 100.00)
           (drawsContent 1)
+          (repaint rects
+            (rect 0.00 0.00 100.00 100.00)
+            (rect 0.00 0.00 100.00 100.00)
+            (rect 0.00 0.00 100.00 100.00)
+          )
         )
       )
     )