Docserver: there is only one.

chrome/common/extensions/docs/templates/private/header_body.html

 <div id="gc-topnav">
   <table><tr>
   <td id="chrome-logo">
-    <a href="." title="Google Chrome {{title}}">
-      <img src="{{static}}/images/chrome-logo.png" alt="">
-      chrome {{platform}}s
+    <a href="/{{platform}}s/" title="Google Chrome {{title}}">
+      <img src="{{static}}/images/chrome-logo.png" alt=""> chrome
     </a>
-    <div id="branch-chooser">
-      <button id="branch-chooser-toggle"
-              class="{{branchInfo.current}}" data-menu="branch-chooser-popup">
-        {{branchInfo.current}} &#x25be;&#x202F;
+    <div id="platform-chooser">
+      <button id="platform-chooser-toggle" data-menu="platform-chooser-popup">
+        {{platform}}s &#x25be;&#x202F;
       </button>
-      <div id="branch-chooser-popup">
-        {{#branchInfo.channels}}
-        {{^isCurrent}}
-        <button class="{{name}}">{{name}}</button>
-        {{/isCurrent}}
-        {{/branchInfo.channels}}
+      <div id="platform-chooser-popup">
+        <button class="apps" data-href="/apps/about_apps.html">apps</button>
+        <button class="extensions" data-href="/extensions">extensions</button>
       </div>
     </div>
   </td>
   <td>
     <ul>
       <li>
         <a href="samples.html"
            title="Sample {{title}} (with source code)">Samples</a>
       </li>
       <li>
         <a href="http://groups.google.com/a/chromium.org/group/chromium-{{platform}}s"
            title="Google Chrome {{title}} developer forum"
            target="_blank">Group</a>
       </li>
       <li>
         <a href="http://stackoverflow.com/questions/tagged/google-chrome-{{platform}}"
            title="[google-chrome-{{platform}}] tag on Stack Overflow"
            target="_blank">Stack overflow</a>
       </li>
     </ul>
   </td>
   </tr></table>
 </div>
 <div id="gc-topnav-space"></div>