Adding or changing any of box-shadow, outline, or border-image-outset does not need a layout..

third_party/WebKit/LayoutTests/svg/repaint/remove-outline-property-on-root-expected.txt

 {
   "bounds": [800, 600],
   "children": [
     {
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "InlineBox",
           "rect": [0, 0, 0, 0],
           "reason": "full"
         },
         {
           "object": "LayoutBlockFlow BODY",
           "rect": [-2, -2, 794, 120],
           "reason": "bounds change"
         },
         {
           "object": "LayoutBlockFlow HTML",
-          "rect": [-2, -2, 802, 122],
+          "rect": [-2, -2, 802, 123],
           "reason": "bounds change"
         },
         {
           "object": "LayoutSVGRoot svg",
           "rect": [-2, -2, 120, 120],
           "reason": "style change"
         },
         {
           "object": "RootInlineBox",
           "rect": [0, 0, 0, 0],
           "reason": "full"
         },
         {
           "object": "RootInlineBox",
           "rect": [0, 0, 0, 0],
           "reason": "full"
         }
       ]
     }
   ]
 }