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

third_party/WebKit/LayoutTests/paint/invalidation/positioned-list-offset-change-repaint-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutListItem (positioned) LI",
           "rect": [8, 60, 214, 236],
           "reason": "forced by layout"
-        },
-        {
-          "object": "LayoutImage IMG",
-          "rect": [8, 60, 214, 232],
-          "reason": "forced by layout"
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutListItem (positioned) LI",
       "reason": "forced by layout"
     },
     {
       "object": "RootInlineBox",
       "reason": "forced by layout"
     },
     {
       "object": "LayoutListMarker (anonymous)",
       "reason": "forced by layout"
     },
     {
       "object": "LayoutImage IMG",
       "reason": "forced by layout"
     },
     {
       "object": "LayoutText #text",
       "reason": "location change"
     }
   ]
 }