Move the tts and ttsEngine APIs out of experimental, and give

chrome/common/extensions/docs/static/manifest.html

 <div id="pageData-name" class="pageData">Formats: Manifest Files</div>
 <div id="pageData-showTOC" class="pageData">true</div>
 
 <p>
 Every extension, installable web app, and theme has a
 <a href="http://www.json.org">JSON</a>-formatted manifest file,
 named <code>manifest.json</code>,
 that provides important information.
 </p>
 
@@ skipping 450 matching lines @@
        For more information see
        <a href="notifications.html">Desktop Notifications</a>.</td>
 </tr>
 <tr>
   <td> "tabs" </td>
   <td> Required if the extension uses the
        <a href="tabs.html">chrome.tabs</a> or
        <a href="windows.html">chrome.windows</a> module. </td>
 </tr>
 <tr>
+  <td> "tts" </td>
+  <td> Required if the extension uses the
+       <a href="tts.html">chrome.tts</a> module. </td>
+</tr>
+<tr>
+  <td> "ttsEngine" </td>
+  <td> Required if the extension uses the
+       <a href="ttsEngine.html">chrome.ttsEngine</a> module. </td>
+</tr>
+<tr>
   <td> "unlimitedStorage"</td>
   <td> Provides an unlimited quota for storing HTML5 client-side data,
        such as databases and local storage files. 
        Without this permission, the extension is limited to
        5 MB of local storage.
 
       <p class="note">
       <b>Note:</b>
       This permission applies only to Web SQL Database and application cache
       (see issue <a href="http://crbug.com/58985">58985</a>).
@@ skipping 48 matching lines @@
 A missing integer is equal to zero.
 For example, 1.1.9.9999 is newer than 1.1.
 </p>
 
 <p>
 For more information, see
 <a href="autoupdate.html">Autoupdating</a>.
 </p>
 
 <!-- [PENDING: Possibly: point to the store/dashboard and make a big deal of the fact that autoupdating is free if you use them.] -->