title: packed chrome extension loses manifest on restart
body: <p>I have a Chrome Extension that is using the experimental sidebar API. It works beautifully when it is unpacked, but if I am running a packed version, and restart my browser, it no longer recognizes that I have asked for the sidebar in the manifest. I start getting these errors everywhere the sidebar is referenced:</p>
  
  <pre><code>Error during experimental.sidebar.getState: This extension has no sidebar specified.
  </code></pre>
  
  <p>This seems like it might be a bug in the sidebar API; or am I missing something obvious?</p>