Merge 159156 - Extensions Docs Server: Fix headings with no IDs

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

 <meta name="doc-family" content="apps">
 <h1>Understand the Architecture</h1>
 
 
 <p>
 Packaged apps integrate closely with a user’s operating system.
 They are designed to be run outside of a browser tab,
 to run robustly in offline and poor connectivity scenarios and
 to have far more powerful capabilities than are available
 in a typical web browsing environment.
@@ skipping 52 matching lines @@
 and can be closed automatically by the system runtime.
 It controls how windows open and close and
 when the app is started or terminated.
 There can only be one “event page” for a packaged app.
 <p>
 
 <p>
 <iframe title="YouTube video player" width="610" height="380" src="http://www.youtube.com/embed/yr1jgREbH8U" frameborder="0" allowfullscreen></iframe>
 </p>
 
-<h3>App lifecycle at a glance</h3>
+<h3 id="lifecycle">App lifecycle at a glance</h3>
 
 <p>
 For detailed instructions on how to use the programming model,
 see <a href="app_lifecycle.html">Manage App Lifecycle</a>.
 Here's a brief summary of the packaged app lifecyle
 to get you started:
 </p>
 
 <br>
 
@@ skipping 79 matching lines @@
 they can only be used to load other app pages.
 You can use the <code>object</code> tag to
 <a href="app_external.html">embed external content</a>;
 this content runs in a separate process from the app.
 </p>
 
 <p>
 <iframe title="YouTube video player" width="610" height="380" src="http://www.youtube.com/embed/EDtiWN42lHs" frameborder="0" allowfullscreen></iframe>
 </p>
 
-<p class="backtotop"><a href="#top">Back to top</a></p>
+<p class="backtotop"><a href="#top">Back to top</a></p>