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

LayoutTests/fast/repaint/align-self-change-keeping-geometry-grid.html

Index: LayoutTests/fast/repaint/align-self-change-keeping-geometry-grid.html
diff --git a/LayoutTests/fast/repaint/align-self-change-keeping-geometry.html b/LayoutTests/fast/repaint/align-self-change-keeping-geometry-grid.html
similarity index 63%
copy from LayoutTests/fast/repaint/align-self-change-keeping-geometry.html
copy to LayoutTests/fast/repaint/align-self-change-keeping-geometry-grid.html
index f6b07be1b38d395e58fe85f18a9a142c9f219282..7fd8feea3b31cf38ea75821b5f79e40788a93cba 100644
--- a/LayoutTests/fast/repaint/align-self-change-keeping-geometry.html
+++ b/LayoutTests/fast/repaint/align-self-change-keeping-geometry-grid.html
@@ -3,27 +3,30 @@
 <script>
 function repaintTest() {
   document.getElementsByClassName('item')[0].style.alignSelf = 'stretch';
-  document.getElementsByClassName('item')[1].style.alignSelf = 'stretch';
 }
 onload = runRepaintTest;
 </script>
 <style>
-.flex {
-  display: flex;
-  align-items: flex-start;
+body {
+  margin: 0;
+}
+#container {
+  display: grid;
+  grid: 100px / 300px;
   width: 200px;
   height: 300px;
   background-color: red;
 }
 .item {
+  grid-row: 1;
+  grid-column: 1;
+  align-self: start;
   background-color: green;
-  border: solid thin blue;
-  width: 100px;
-  height: 300px;
 }
 </style>
 <p style="height: 20px">There should be no invalidations because align-self style change causes no visual change.</p>
-<div class="flex">
-  <div class="item"></div>
-  <div class="item"></div>
+<div id="container">
+  <div class="item">
+    <div style="height: 300px"></div>
+  </div>
 </div>