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

third_party/WebKit/LayoutTests/platform/linux/paint/invalidation/search-field-cancel-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutBlockFlow DIV id='inner-editor'",
           "rect": [11, 47, 137, 16],
           "reason": "forced by layout"
-        },
-        {
-          "object": "LayoutText #text",
-          "rect": [11, 47, 58, 16],
-          "reason": "layoutObject insertion"
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutBlockFlow DIV id='inner-editor'",
       "reason": "forced by layout"
     },
     {
       "object": "RootInlineBox",
       "reason": "forced by layout"
     },
     {
       "object": "LayoutText #text",
       "reason": "layoutObject insertion"
     },
     {
       "object": "InlineTextBox 'some text'",
       "reason": "layoutObject insertion"
     }
   ]
 }