title: Chrome extension: how to use serial port (now that apps are sunsetting)?
body: <p><strong>Aim</strong>: I am attempting to write a little "thing" that can talk from my browser to the COM port of an Arduino.</p>
  
  <p><strong>Issue</strong>: My first attempt is to write an extension. Therefore I am requesting permission for <code>serial</code> in my manifest file. When loading the unpackaged extension via developer mode I receive the following error: <code>'serial' is only allowed for packaged apps, but this is a extension.</code></p>
  
  <p><a href="https://developer.chrome.com/extensions/apps" rel="noreferrer">I see here</a> that <code>packaged app</code> is an outdated term and I guess they just mean <code>Chrome app</code>. Now unfortunately it seems that Chrome is also discontinuing these Chrome apps as <a href="https://blog.chromium.org/2016/08/from-chrome-apps-to-web.html" rel="noreferrer">discussed here</a>.</p>
  
  <p><strong>Question</strong>: So how should I access the <code>serial</code> functionality of Chrome apps/extensions/whatever new name you come up with?</p>