Update reason after full paint invalidation

third_party/WebKit/LayoutTests/paint/invalidation/clip-with-layout-delta-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutBlockFlow (relative positioned) DIV",
           "rect": [108, 8, 100, 100],
           "reason": "background obscuration change"
         },
         {
-          "object": "LayoutBlockFlow SPAN id='t2' class='blue'",
-          "rect": [108, 8, 100, 100],
-          "reason": "style change"
-        },
-        {
           "object": "LayoutBlockFlow DIV",
           "rect": [8, 8, 100, 100],
           "reason": "background obscuration change"
-        },
-        {
-          "object": "LayoutBlockFlow SPAN id='t1'",
-          "rect": [8, 8, 100, 100],
-          "reason": "style change"
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutBlockFlow DIV",
       "reason": "background obscuration change"
     },
     {
@@ skipping 28 matching lines @@
       "object": "LayoutText #text",
       "reason": "forced by layout"
     },
     {
       "object": "InlineTextBox '\u00A0'",
       "reason": "forced by layout"
     }
   ]
 }