Move chrome.experimental.app.onLaunched event handler to chrome.app.runtime.onLaunched.

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

 <meta name="doc-family" content="apps">
 <div id="pageData-name" class="pageData">Manage App Lifecycle</div>
 <div id="pageData-showTOC" class="pageData">true</div>
 
 <p>
 The app runtime and event page are responsible
 for managing the app lifecycle.
 The app runtime manages app installation,
 controls the event page,
 and can shutdown the app at anytime.
@@ skipping 57 matching lines @@
 }
 </pre>
 
 <p>
 Your event page must include the <code>onLaunched()</code> function.
 This function is called
 when your application is launched in any way:
 </p>
 
 <pre>
-chrome.experimental.app.onLaunched.addListener(function() { 
+chrome.app.runtime.onLaunched.addListener(function() { 
   // Tell your app what to launch and how.
 });
 </pre>
 
 <h3>Create windows</h3>
 
 <p>
 An event page may create one or more windows at its discretion.
 By default, these windows are created with a script connection
 to the event page and are directly scriptable by the event page.
 </p>
 
 <p>
 Windows can either be shells or panels.
 Shell windows have no browser chrome.
 Panel windows are the same as shell windows,
 except they have different size and position restrictions,
 for example, a chat panel.
 </p>
 
 <p>Here's a sample <code>background.js</code>
   with a 'shell' window:</p>
 
 <pre>
-chrome.experimental.app.onLaunched.addListener(function() {
+chrome.app.runtime.onLaunched.addListener(function() {
   chrome.app.window.create('main.html', {
     width: 800,
     height: 600,
     minWidth: 800,
     minHeight: 600,
     left: 100,
     top: 100,
     type: 'shell'
   });
 });
 </pre>
 
 <p>Here's a sample <code>background.js</code>
   with a 'panel' window:
 </p>
 
 <pre>
-chrome.experimental.app.onLaunched.addListener(function() {
+chrome.app.runtime.onLaunched.addListener(function() {
   chrome.app.window.create('index.html', {
     width: 400,
     height: 200,
     type: 'panel'
   });
 });
 </pre>
 
 <h3>Including Launch Data</h3>
 
@@ skipping 89 matching lines @@
 Keep the clean-up tasks synchronous and simple.
 </p>
 
 <pre>
 chrome.runtime.onSuspend.addListener(function() { 
   // Do some simple clean-up tasks.
 });
 </pre>
 
 <p class="backtotop"><a href="#top">Back to top</a></p>