Don't invalidate rect if it's covered by fully invalidated parent's visual rect

third_party/WebKit/LayoutTests/platform/linux/paint/invalidation/line-flow-with-floats-6-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutText #text",
@@ skipping 12 matching lines @@
         },
         {
           "object": "LayoutText #text",
           "rect": [134, 360, 131, 19],
           "reason": "forced by layout"
         },
         {
           "object": "LayoutBlockFlow (floating) SPAN id='blueFloat'",
           "rect": [14, 363, 48, 65],
           "reason": "forced by layout"
-        },
-        {
-          "object": "LayoutText #text",
-          "rect": [28, 363, 20, 20],
-          "reason": "layoutObject insertion"
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutText #text",
       "reason": "forced by layout"
     },
     {
@@ skipping 96 matching lines @@
       "object": "InlineTextBox 'hedgehogs; and in\n'",
       "reason": "forced by layout"
     },
     {
       "object": "InlineTextBox 'a very short time '",
       "reason": "forced by layout"
     }
   ]
 }