title: Unable to download blob in firefox due to CSP error
body: <p>I am trying to download a PDF file from the blob. The whole thing is in the <code>iframe</code> and when I try to download it, it throws this error in console: <code>Content Security Policy: The page’s settings blocked the loading of a resource at blob:http://localhost:8080/myApp/31d389m6-8njb-n7gv-427n-bm86ynte36hc(&quot;child-src&quot;)</code>, I have tried this:</p>
  <pre><code>const url = URL.createObjectURL(blob);
  const a = document.createElement('a');
  a.href = url;
  a.download = fileName || 'download';
  document.body.appendChild(a);
  const clickHandler = function() {
      setTimeout(function(){
          URL.revokeObjectURL(url);
          this.removeEventListener('click', clickHandler);
          a.parentNode.removeChild(a);
      }, 150);
  };
  a.addEventListener('click', clickHandler, false);
  a.click();
  </code></pre>
  <p>I have added <code>&lt;meta http-equiv=&quot;X-UA-Compatible&quot; content=&quot;IE=edge&quot;&gt;</code> to both main page and as well as in the iframe, still this error is there. It is working on other browsers like chrome and edge. Is there anything I am missing?</p>