Add some more info on the event page docs to explain how to switch from

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

 <div id="pageData-name" class="pageData">Event Pages</div>
 <div id="pageData-showTOC" class="pageData">true</div>
 
 <p>
 Event pages are very similar to
 <a href="background_pages.html">background pages</a>,
 with one important difference:
 event pages are loaded only when they are needed.
 When the event page is not actively doing something,
 it is unloaded, freeing memory and other system resources.
@@ skipping 47 matching lines @@
 </p>
 
 <p>
 Once the event page has been idle a short time
 (a few seconds), the
 <code><a href="runtime.html#event-onSuspend">chrome.runtime.onSuspend</a></code>
 event is dispatched. The event page has a few more seconds to handle this
 event before it is forcibly unloaded. Note that once the event is dispatched,
 new activity will not keep the event page open.
 </p>
+
+<h2 id="transition">Convert background page to event page</h2>
+<p>
+Follow this checklist to convert your extension's
+(persistent) background page to an event page.
+
+<ol>
+  <li>Add <code>"persistent": false</code> to your manifest as shown above.
+
+  <li>Register to receive any events your extension is interested in
+  each time the event page is loaded. The event page will be loaded once
+  for each new version of your extension. After that it will only be
+  loaded to deliver events.

[Aaron Boodman, 2012/07/23 23:07:29]

.append(" you have registered for") ?

[Matt Perry, 2012/07/24 00:11:02]

Done.

+
+  <li>If you need to do some initialization when your extension is
+  installed or upgraded, listen to the
+  <code><a href="runtime.html#event-onInstalled">chrome.runtime.onInstalled</a></code>
+  event.
+
+  <li>Listen to the
+  <code><a href="runtime.html#event-onSuspend">chrome.runtime.onSuspend</a></code>
+  event if you need to do last second cleanup before your event page
+  is shut down. However, we recommend persisting periodically instead.
+  That way if your extension crashes without receiving
+  <code>onSuspend</code>, no data will typically be lost.
+
+  <li>If you need to keep runtime state in memory throughout a browser

[Aaron Boodman, 2012/07/23 23:07:29]

Makes more sense if this point goes before the previous one.

[Matt Perry, 2012/07/24 00:11:02]

Done.

+  session, use the <a href="storage.html">storage API</a> or
+  IndexedDB. Since the event page does not stay loaded for long, you
+  can no longer rely on global variables for runtime state.
+
+  <li>If your extension uses <code>window.setTimeout()</code> or
+  <code>window.setInterval()</code>, switch to using the
+  <a href="alarms.html">alarms API</a> instead. DOM-based timers won't
+  be honored if the event page shuts down.
+
+  <li>If your extension uses,
+  <code><a href="extension.html#method-getBackgroundPage">chrome.extension.getBackgroundPage()</a></code>,
+  switch to
+  <code><a href="runtime.html#method-getBackgroundPage">chrome.runtime.getBackgroundPage()</a></code>
+  instead.

[Aaron Boodman, 2012/07/23 23:07:29]

.append(" The newer method is asynchronous so that it can start the background
page if necessary before returning it.");

[Matt Perry, 2012/07/24 00:11:02]

Done.

+
+  <li>If you're using <a href="messaging.html">message passing</a>, be sure
+  to close unused message ports. The event page will not shut down until all
+  message ports are closed.
+</ol>
+</p>