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

third_party/WebKit/LayoutTests/platform/linux/paint/invalidation/text-match-document-change-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutBlockFlow DIV id='to-be-changed'",
           "rect": [18, 130, 269, 40],
           "reason": "full"
         },
         {
           "object": "LayoutText #text",
           "rect": [18, 130, 235, 39],
           "reason": "layoutObject removal"
         },
         {
-          "object": "LayoutText #text",
-          "rect": [18, 130, 77, 19],
-          "reason": "layoutObject insertion"
-        },
-        {
           "object": "LayoutView #document",
           "rect": [295, 102, 15, 400],
           "reason": "scroll"
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutText #text",
@@ skipping 15 matching lines @@
       "object": "LayoutText #text",
       "reason": "layoutObject insertion"
     },
     {
       "object": "InlineTextBox 'After change'",
       "reason": "layoutObject insertion"
     }
   ]
 }