Migrate svg layout tests to use slimming paint by default

LayoutTests/svg/repaint/foreign-object-repaint-expected.txt

 {
   "bounds": [800, 600],
   "children": [
     {
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "repaintRects": [
         [129, 200, 142, 142],
         [50, 50, 100, 100]
+      ],
+      "paintInvalidationClients": [
+        "LayoutBlockFlow div id='div1'",
+        "LayoutBlockFlow div id='div2'"
       ]
     }
   ]
 }