Cleanup: Don't close single tags.

chrome/browser/resources/sync_internals/about.html

 <script src="chrome://sync-internals/about.js"></script>
 
 <style>
 div#aboutInfo {
   -webkit-columns: 3;
 }
 
 div#aboutInfo h2 {
   color: #4a8ee6;
   font-size: 100%;
@@ skipping 76 matching lines @@
         <td class="detail" jscontent="stat_name" width=50%></td>
         <td class="value" jscontent="stat_value" width=50%></td>
       </tr>
     </table>
   </div>
 
   <div class="section">
     <h2>Type Info</h2>
     <table id="typeInfo">
       <tr jsselect="type_status" jsvalues="class:$this.status">
-        <td jscontent="name" width=50% />
-        <td jscontent="value" width=50% />
+        <td jscontent="name" width=50%></td>
+        <td jscontent="value" width=50%></td>
       </tr>
     </table>
   </div>
 
   <div class="section" jsdisplay="unrecoverable_error_detected">
     <p>
       <span class="err" jscontent="unrecoverable_error_message"></span>
     </p>
   </div>
 
   <div class="section" jsdisplay="actionable_error_detected">
     <p>
       <h2>Actionable Error</h2>
       <table id="actionableError">
         <tr jsselect="actionable_error">
-          <td jscontent="stat_name"/>
-          <td jscontent="stat_value"/>
+          <td jscontent="stat_name"></td>
+          <td jscontent="stat_value"></td>
         </tr>
       </table>
     </p>
   </div>
 </div>