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

third_party/WebKit/LayoutTests/platform/linux/paint/invalidation/line-overflow-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutText #text",
           "rect": [7, 122, 197, 79],
           "reason": "forced by layout"
         },
         {
           "object": "LayoutText #text",
           "rect": [8, 82, 190, 59],
           "reason": "forced by layout"
         },
         {
           "object": "LayoutInline SPAN id='t'",
           "rect": [47, 92, 33, 49],
           "reason": "style change"
         },
         {
           "object": "LayoutInline SPAN id='t'",
           "rect": [77, 122, 33, 19],
           "reason": "style change"
-        },
-        {
-          "object": "LayoutText #text",
-          "rect": [77, 122, 33, 19],
-          "reason": "forced by layout"
-        },
-        {
-          "object": "LayoutText #text",
-          "rect": [47, 122, 33, 19],
-          "reason": "forced by layout"
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutText #text",
       "reason": "forced by layout"
     },
     {
@@ skipping 40 matching lines @@
       "object": "InlineTextBox 'Integer sollicitudin nisi ut urna'",
       "reason": "forced by layout"
     },
     {
       "object": "InlineTextBox 'blandit convallis.'",
       "reason": "forced by layout"
     }
   ]
 }