Remove NonCompositedContentHost -- Take 2

LayoutTests/compositing/geometry/layer-due-to-layer-children-switch-expected.txt

 This content is in the parent
 Box should switch between perspective and flat
 
 First dump layer tree:
 
 Second dump layer tree:
 (GraphicsLayer
   (bounds 800.00 600.00)
   (children 1
     (GraphicsLayer
       (bounds 800.00 600.00)
       (contentsOpaque 1)
+      (drawsContent 1)
       (children 1
         (GraphicsLayer
           (position 8.00 8.00)
           (bounds 242.00 192.00)
           (drawsContent 1)
           (children 1
             (GraphicsLayer
               (position 121.00 39.00)
               (bounds 250.00 100.00)
               (contentsOpaque 1)
               (drawsContent 1)
               (backgroundColor #008000)
               (transform [0.71 0.00 -0.71 0.00] [0.00 1.00 0.00 0.00] [0.71 0.00 0.71 -0.00] [-50.00 10.00 100.00 0.83])
             )
           )
         )
       )
     )
   )
 )
 
 Third dump layer tree: