Paint backgrounds of a table section/row in one display item

third_party/WebKit/LayoutTests/paint/invalidation/table/animated-row-background-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutTableRow TR id='row'",
           "rect": [8, 10, 210, 102],
           "reason": "full"
         },
         {
           "object": "LayoutImage IMG id='image'",
           "rect": [8, 114, 50, 50],
           "reason": "full"
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
-      "object": "LayoutTableCell TD id='cell1'",
-      "reason": "style change"
-    },
-    {
-      "object": "LayoutTableCell TD id='cell2'",
-      "reason": "style change"
-    },
-    {
       "object": "LayoutTableRow TR id='row'",
       "reason": "full"
     },
     {
       "object": "LayoutImage IMG id='image'",
       "reason": "full"
     }
   ]
 }