Auto-rebaseline for r189636

LayoutTests/platform/mac/compositing/repaint/fixed-pos-with-abs-pos-child-scroll-expected.txt

 Hi!
 {
   "bounds": [785, 4021],
   "children": [
     {
       "bounds": [785, 4021],
       "contentsOpaque": true,
       "drawsContent": true,
       "repaintRects": [
         [425, 980, 360, 90],
         [425, 980, 360, 90],
-        [425, 980, 22, 16],
-        [425, 980, 22, 16],
+        [425, 980, 22, 18],
+        [425, 980, 22, 18],
         [425, 480, 360, 90],
         [425, 480, 360, 90],
-        [425, 480, 22, 16],
-        [425, 480, 22, 16]
+        [425, 480, 22, 18],
+        [425, 480, 22, 18]
       ]
     }
   ]
 }