Auto-rebaseline for r168335

LayoutTests/platform/mac/virtual/softwarecompositing/overflow/do-not-opt-non-stacking-context-descendants-into-composited-scrolling-expected.txt

 This test ensures that the descendants of children of non-stacking context overflow-scroll divs do not get promoted needlessly. Only the immediate child of an overflow-scroll div, or an unclipped descendant, need to be promoted.
 
 (GraphicsLayer
   (bounds 1832.00 1682.00)
   (children 1
     (GraphicsLayer
       (bounds 1832.00 1682.00)
       (contentsOpaque 1)
       (drawsContent 1)
       (children 4
@@ skipping 45 matching lines @@
           (position 39.00 641.00)
           (bounds 180.00 300.00)
           (contentsOpaque 1)
           (drawsContent 1)
           (backgroundColor #808080)
           (children 1
             (GraphicsLayer
               (position 0.00 -200.00)
               (bounds 100.00 100.00)
               (contentsOpaque 1)
-              (drawsContent 1)
-              (backgroundColor #000000)
             )
           )
         )
       )
     )
   )
 )