Enable position:sticky for <thead> and <tr> elements

third_party/WebKit/LayoutTests/fast/css/sticky/sticky-table-thead-multirow-top.html

Index: third_party/WebKit/LayoutTests/fast/css/sticky/sticky-table-thead-multirow-top.html
diff --git a/third_party/WebKit/LayoutTests/fast/css/sticky/nested/sticky-nested-table.html b/third_party/WebKit/LayoutTests/fast/css/sticky/sticky-table-thead-multirow-top.html
similarity index 53%
copy from third_party/WebKit/LayoutTests/fast/css/sticky/nested/sticky-nested-table.html
copy to third_party/WebKit/LayoutTests/fast/css/sticky/sticky-table-thead-multirow-top.html
index 6c926db62c2ccce16da0339a039ccc95d2d844ae..e1f7e4c4b2d388c452101a80713b6fc331a11dbb 100644
--- a/third_party/WebKit/LayoutTests/fast/css/sticky/nested/sticky-nested-table.html
+++ b/third_party/WebKit/LayoutTests/fast/css/sticky/sticky-table-thead-multirow-top.html
@@ -1,17 +1,12 @@
 <style>
-body {
-  margin: 0;
-}
 
 table {
-  background: red;
   border-collapse: collapse;
 }
 
 td, th {
-  height: 50px;
-  width: 50px;
-  padding: 0;
+  height: 40px;
+  width: 40px;
 }
 
 th {
@@ -19,16 +14,18 @@ th {
 }
 
 .scroller {
-  overflow: hidden; /* hide scrollbars */
-  width: 100px;
-  height: 200px;
-  outline: 2px solid black;
+  overflow: auto;
+  height: 400px;
 }
 
 .sticky {
   position: sticky;
   top: 25px;
 }
+
+.padding {
+  height: 500px;
+}
 </style>
 
 <script>
@@ -49,22 +46,29 @@ window.addEventListener('load', function() {
 </script>
 
 <div class="scroller">
+
   <table>
     <thead class="sticky">
-      <tr class="sticky">
-        <th class="sticky"></th>
+      <tr>
+        <th rowspan="2"></th>
+        <th></th>
+      </tr>
+      <tr>
+        <th style="background: fuchsia;"></th>
       </tr>
     </thead>
     <tbody>
-      <tr><td></td></tr>
-      <tr><td></td></tr>
-      <tr><td></td></tr>
-      <tr><td></td></tr>
-      <tr><td></td></tr>
-      <tr><td></td></tr>
-      <tr><td></td></tr>
-      <tr><td></td></tr>
-      <tr><td></td></tr>
+      <tr><td></td><td></td></tr>
+      <tr><td></td><td></td></tr>
+      <tr><td></td><td></td></tr>
+      <tr><td></td><td></td></tr>
+      <tr><td></td><td></td></tr>
+      <tr><td></td><td></td></tr>
+      <tr><td></td><td></td></tr>
+      <tr><td></td><td></td></tr>
     </tbody>
-  </table>
+    </table>
+
+  <div class="padding"></div>
+
 </div>