title: Microsoft Edge Browser Extension ajax for CORS request Origin Header not sent
body: <p>I am creating browser extension for Firefox, Chrome and Edge. I have been able to get my extension working in Firefox and Chrome but stuck with an issue on Edge.</p>
  
  <p>When my extension loads it makes ajax GET call and fetches some initialization data.
  Firefox sends <code>Origin</code> header when I am making the ajax call, which helps me set <code>Access-Control-Allow-Origin</code> accordingly.</p>
  
  <p>With Edge there is no <code>Origin</code> header going out with request and my check fails resulting in no response header being set and call fails with error as. </p>
  
  <blockquote>
    <p>SEC7120: [CORS] The origin
    'ms-browser-extension://Manager_F14DC7EC297D4EDABB8E56840AE117D6' did
    not find
    'ms-browser-extension://Manager_F14DC7EC297D4EDABB8E56840AE117D6' in
    the Access-Control-Allow-Origin response header for cross-origin 
    resource at '<a href="https://example.com/api/i18n?_=1552907931096" rel="nofollow noreferrer">https://example.com/api/i18n?_=1552907931096</a>'.</p>
  </blockquote>
  
  <p>Am I missing some thing here, manifest.json should contain some instruction specific to Edge.
  <em>Microsoft Edge version is 42.17134.1.0</em> </p>
  
  <p>Above scenario is happening during development, I am accessing the extension loaded from file system.</p>