echo.html | Explore in Territory

<!DOCTYPE html>
<html>
  <head><title>echo</title></head>
  <body>
    <script>
      // Use the "echo" port that was bound to the scripting context by the
      // browsertest.
      echo.onmessage = function(msg) {
        echo.postMessage('ack ' + msg.data);
      }
    </script>
  </body>
</html>

chromium/fuchsia_web/runners/cast/testdata/echo.html