Paint collapsed borders of a table as one display item

third_party/WebKit/LayoutTests/paint/invalidation/table-section-repaint-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
+          "object": "LayoutTable TABLE",
+          "rect": [8, 308, 60, 83],
+          "reason": "forced by layout"
+        },
+        {
           "object": "LayoutTableCell TD class='half'",
           "rect": [8, 353, 60, 38],
           "reason": "bounds change"
         },
         {
           "object": "LayoutTableCell TD class='half'",
           "rect": [8, 338, 60, 38],
           "reason": "bounds change"
         },
         {
@@ skipping 73 matching lines @@
         },
         {
           "object": "LayoutBlockFlow CAPTION id='caption1' class='blue half'",
           "rect": [8, 8, 60, 30],
           "reason": "became invisible"
         },
         {
           "object": "LayoutTableCell TD class='red half'",
           "rect": [8, 8, 60, 30],
           "reason": "bounds change"
-        },
-        {
-          "object": "LayoutTable TABLE",
-          "rect": [8, 372, 60, 19],
-          "reason": "incremental"
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutBlockFlow CAPTION id='caption1' class='blue half'",
       "reason": "became invisible"
     },
     {
@@ skipping 47 matching lines @@
     {
       "object": "LayoutTableRow TR",
       "reason": "location change"
     },
     {
       "object": "LayoutTableCell TD class='red half'",
       "reason": "bounds change"
     },
     {
       "object": "LayoutTable TABLE",
-      "reason": "incremental"
+      "reason": "forced by layout"
     },
     {
       "object": "LayoutTableRow TR",
       "reason": "location change"
     },
     {
       "object": "LayoutTableCell TD class='half'",
       "reason": "bounds change"
     },
     {
       "object": "LayoutTableRow TR",
       "reason": "location change"
     },
     {
       "object": "LayoutTableCell TD class='half'",
       "reason": "bounds change"
     }
   ]
 }