[DocServer] Fixed Sample Links

chrome/common/extensions/docs/templates/articles/extensions_index.html

 <h1 id="What-are-extensions">What are extensions?</h1>
 
 <p>
   Extensions are small software programs that
   can modify and enhance the functionality of the Chrome browser.
   You write them using web technologies such as
   HTML, JavaScript, and CSS.
 </p>
 
 <p>
   <img src="{{static}}/images/index/gmail-small.png"
        width="91"
        height="35"
        align="right"
        style="margin-top:0px; margin-left:0.5em"
        alt="A screenshot of an extension's icon in the browser bar">
   Extensions have little to no user interface.
   For example, the image to the right shows the icon
   that provides the UI for the
-  <a href="samples.html#gmail">Gmail extension</a>.
+  <a href="samples.html#google-mail-checker">Google Mail Checker extension</a>.
 </p>
 
 <p>
   Extensions bundle all their files
   into a single file that the user downloads and installs.
   This bundling means that, unlike ordinary web apps,
   extensions don't need to depend
   on content from the web.
 </p>
 
@@ skipping 29 matching lines @@
 <h2 id="Featured-videos">Featured videos</h2>
 
 <p>
   <a href="http://www.youtube.com/view_play_list?p=CA101D6A85FE9D4B">Technical videos</a> <br>
   <a href="http://www.youtube.com/view_play_list?p=38DF05697DE372B1">Developer snapshots</a> (below)
 </p>
 
 <p>
   <iframe title="YouTube video player" width="300" height="199" src="//www.youtube.com/embed/wRDPTnY3yO8?rel=0" frameborder="0" allowfullscreen=""></iframe>
 </p>