[CSS Grid Layout] New alignment related repaint layout tests.

LayoutTests/virtual/slimmingpaint/fast/repaint/justify-self-overflow-change-expected.txt

 {
   "bounds": [800, 600],
   "children": [
     {
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "repaintRects": [
-        [1, 53, 150, 150],
+        [150, 52, 50, 300],
         [0, 52, 200, 300],
-        [0, 52, 152, 152],
+        [0, 52, 150, 300],
+        [0, 52, 150, 150],
         [0, 16, 800, 336],
         [0, 0, 800, 352],
-        [-51, 53, 150, 150],
-        [-52, 52, 252, 300],
-        [-52, 52, 152, 152],
-        [-52, 16, 852, 336],
-        [-52, 0, 852, 352]
+        [-50, 52, 250, 300],
+        [-50, 52, 150, 300],
+        [-50, 52, 150, 150],
+        [-50, 16, 850, 336],
+        [-50, 0, 850, 352]
       ],
       "paintInvalidationClients": [
         "LayoutBlockFlow HTML",
         "LayoutBlockFlow BODY",
         "LayoutGrid DIV id='container'",
         "LayoutBlockFlow DIV class='item1'",
-        "LayoutBlockFlow DIV"
+        "LayoutBlockFlow DIV",
+        "LayoutBlockFlow DIV class='item2'"
       ]
     }
   ]
 }