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

third_party/WebKit/LayoutTests/platform/win/paint/invalidation/caret-subpixel-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutTextControl INPUT id='target'",
           "rect": [8, 8, 224, 22],
           "reason": "subtree"
-        },
-        {
-          "object": "LayoutBlockFlow DIV id='inner-editor'",
-          "rect": [10, 11, 201, 16],
-          "reason": "subtree"
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutTextControl INPUT id='target'",
       "reason": "subtree"
     },
     {
       "object": "LayoutBlockFlow DIV id='inner-editor'",
       "reason": "subtree"
     },
     {
       "object": "Caret",
       "reason": "caret"
     }
   ]
 }