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

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

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutTextControl TEXTAREA id='editor'",
           "rect": [7, 7, 183, 40],
           "reason": "subtree"
         },
         {
           "object": "LayoutText #text",
           "rect": [9, 11, 179, 16],
           "reason": "subtree"
         },
         {
-          "object": "LayoutBlockFlow DIV id='inner-editor'",
-          "rect": [11, 11, 175, 16],
-          "reason": "subtree"
-        },
-        {
           "object": "LayoutTextControl TEXTAREA id='editor'",
           "rect": [9, 30, 164, 15],
           "reason": "scroll"
         },
         {
           "object": "LayoutTextControl TEXTAREA id='editor'",
           "rect": [173, 30, 15, 15],
           "reason": "scroll"
         }
       ]
@@ skipping 28 matching lines @@
       "object": "LayoutText #text",
       "reason": "subtree"
     },
     {
       "object": "InlineTextBox '------------------------------------------------------------'",
       "reason": "subtree"
     }
   ]
 }