<!DOCTYPE HTML>
<html>
<head>
  <meta charset="utf-8">
  <meta http-equiv="Content-Security-Policy"
        content= "img-src 'none'; script-src 'unsafe-inline'; report-uri http://www.example.com; frame-ancestors https:; sandbox allow-scripts">
  <title>Bug 663570 - Implement Content Security Policy via meta tag</title>
</head>
<body>

  <!-- try to load an image which is forbidden by meta CSP -->
  <img id="testimage" src="http://mochi.test:8888/tests/image/test/mochitest/blue.png"></img>

  <script type="application/javascript">
    var myImg = document.getElementById("testimage");
    myImg.onload = function(e) {
      window.parent.postMessage({result: "img-loaded"}, "*");
    };
    myImg.onerror = function(e) {
      window.parent.postMessage({result: "img-blocked"}, "*");
    };
  </script>

</body>
</html>