Extension docs server: CSS and content tweaks.

chrome/common/extensions/docs/server2/templates/private/header_body.html

 {{?branchInfo.showWarning}}
 <div id="branchWarning" class="displayModeWarning">
   <span>WARNING: this is the {{branchInfo.current}} documentation. It may not work with the stable release of Chrome.</span>
   <select id="branchChooser">
     <option value="">Choose a different version...</option>
     {{#branchInfo.channels}}
     <option value="{{path}}">{{name}}</option>
     {{/}}
   </select>
 </div>
 {{/}}
 <a id="top"></a>
 <div id="header">
   <div id="logo">
     <a href="http://code.google.com/"><img src="{{static}}/images/chrome_logo.gif" alt="Google Code Labs" style="border:0; margin:0;"></a>
   </div>
   <div id="cse"></div>
-  <span class="greytext">e.g. "page action" or "tabs"</span>
+  <span id="cseSampleText" hidden>e.g. "page action" or "tabs"</span>
 </div>
 <a id="gc-topnav-anchor"></a>
 <div id="gc-topnav">
   <h1>Google Chrome {{title}}</h1>
   <ul id="home" class="gc-topnav-tabs">
     <li id="home_link">
       <a href="index.html" title="Google Chrome {{title}} home page"><div>Home</div></a>
     </li>
     <li id="docs_link">
       <a href="docs.html" title="Official Google Chrome {{title}} documentation"><div>Docs</div></a>
     </li>
     <li id="faq_link">
       <a href="faq.html" title="Answers to frequently asked questions about Google Chrome {{title}}"><div>FAQ</div></a>
     </li>
     <li id="samples_link">
       <a href="samples.html" title="Sample {{title}} (with source code)"><div>Samples</div></a>
     </li>
     <li id="group_link">
       <a href="http://groups.google.com/a/chromium.org/group/chromium-extensions" title="Google Chrome {{title}} developer forum"><div>Group</div></a>
     </li>
     <li id="so_link">
       <a href="http://stackoverflow.com/questions/tagged/google-chrome-extension" title="[google-chrome-extension] tag on Stack Overflow"><div>Questions?</div></a>
     </li>
   </ul>
 </div>