Auto-rebaseline for r191480

LayoutTests/compositing/layer-creation/scroll-blocks-on-default-expected.txt

 Verify we get the default scroll-blocks-on mode applied to the viewport, no additional layers created (even with an iframe), and no scroll-blocks-on mode applied to any other layer.
 
 {
   "bounds": [800, 600],
   "children": [
     {
       "bounds": [800, 600],
-      "scrollBlocksOn": ["StartTouch", "WheelEvent"],
+      "scrollBlocksOn": [
+        "StartTouch",
+        "WheelEvent"
+      ],
       "contentsOpaque": true,
       "drawsContent": true,
       "children": [
         {
           "position": [8, 8],
           "bounds": [20, 20]
         }
       ]
     }
   ]
 }