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

third_party/WebKit/LayoutTests/compositing/squashing/squash-transform-repainting-child-expected.txt

 CASE 1, original layer tree
 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true
     },
     {
@@ skipping 118 matching lines @@
         [0.707106781186548, 0.707106781186548, 0, 0],
         [-0.707106781186548, 0.707106781186548, 0, 0],
         [0, 0, 1, 0],
         [0, 0, 0, 1]
       ],
       "paintInvalidations": [
         {
           "object": "LayoutBlockFlow (positioned) DIV class='box middle'",
           "rect": [0, 0, 100, 100],
           "reason": "style change"
-        },
-        {
-          "object": "LayoutBlockFlow (positioned) DIV class='smallbox'",
-          "rect": [20, 25, 50, 50],
-          "reason": "style change"
         }
       ]
     },
     {
       "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (positioned) DIV class='box top')",
       "position": [180, 180],
       "bounds": [100, 100],
       "drawsContent": true
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutBlockFlow (positioned) DIV class='box middle'",
       "reason": "style change"
     },
     {
       "object": "LayoutBlockFlow (positioned) DIV class='smallbox'",
       "reason": "style change"
     }
   ]
 }