Extension doc changes (nothing buildable or testable) - Add boilerplate line for experimental api...

chrome/common/extensions/docs/template/api_template.html

   <div id="gc-container" class="labs">
       <div id="devModeWarning">
         You are viewing extension docs in chrome via the 'file:' scheme: are you expecting to see local changes when you refresh? You'll need run chrome with --allow-file-access-from-files.
       </div>
       <!-- SUBTEMPLATES: DO NOT MOVE FROM THIS LOCATION -->
       <!-- In particular, sub-templates that recurse, must be used by allowing
            jstemplate to make a copy of the template in this section which
            are not operated on by way of the jsskip="true" -->
       <div jsskip="true" style="display:none">
 
@@ skipping 246 matching lines @@
                            href="#id-anchor">id</a>
                       </li>
                     </ol>
                   </li>
                 </ol>
               </li>
           </ol>
         </div>
         <!-- /TABLE OF CONTENTS -->
 
+        <!-- Standard content lead-in for experimental API pages -->
+        <p jsdisplay="isExperimentalAPIPage();" id="classSummary">
+          For information on how to use experimental APIs, see the <a href="experimental.html">chrome.experimental.* APIs</a> page.
+        </p>
+
         <!-- STATIC CONTENT PLACEHOLDER -->
         <div id="static"></div>
 
         <!-- API PAGE -->
         <div class="apiPage" jsselect="apiDefinition">
         <a name="apiReference"></a>
         <h2 jscontent="'API reference: ' + getModuleName()">API reference: chrome.apiname </h2>
 
           <!-- PROPERTIES -->
           <div jsdisplay="$this.properties" class="apiGroup">
@@ skipping 179 matching lines @@
     _uanchor=1;
     _uff=0;
     urchinTracker();
   }
   catch(e) {/* urchinTracker not available. */}
 </script>
 <!-- end analytics -->
       </div>
     </div> <!-- /gc-footer -->
   </div> <!-- /gc-container -->