Use rowgroup and columgroup properties to expose table headers.

LayoutTests/accessibility/table-header-column-row.html

Index: LayoutTests/accessibility/table-header-column-row.html
diff --git a/LayoutTests/accessibility/table-header-column-row.html b/LayoutTests/accessibility/table-header-column-row.html
index 6f99810a191bde7e5ee64b822649f92896299cea..2e57686aa79878f1bf7a748f9cdd558592171c83 100644
--- a/LayoutTests/accessibility/table-header-column-row.html
+++ b/LayoutTests/accessibility/table-header-column-row.html
@@ -59,6 +59,38 @@
     <td>data</td>
   </tr>
 </table>
+<table width="50%" border="1">
+  <caption>
+    row header and column header (3)
+  <caption>
+  <col>
+  <colgroup span="2"></colgroup>
+  <tr>
+    <td rowspan="2"></td>
+    <th colspan="2" scope="colgroup">col head</th>
+  </tr>
+  <tr>
+    <th scope="col">col head</th>
+    <th scope="col">col head</th>
+  </tr>
+  <tr>
+    <th scope="row">row head</th>
+    <td>data</td>
+    <td>data</td>
+  </tr>
+</table>
+<table width="50%" border="1">
+  <caption>
+    row header and column header (4)
+  <caption>
+  <tr>
+    <th rowspan="2" scope="rowgroup">row head</th>
+    <th scope="col">col head</th>
+  </tr>
+  <tr>
+    <th scope="row">row head</th>
+  </tr>
+</table>
 <p>End of test</p>
 <p id="description"></p>
 <div id="console"></div>