  - Open https://mozilla.github.io/pdf.js/web/viewer.html
  - Open a pdf with some XFA (for example the on in https://github.com/mozilla/pdf.js/issues/13679#issue-937616350)

The pdf is not correctly displayed because `enableXfa` is false.

@Snuffleupagus, the pref is set to true in Firefox nightly, is there anything blocking setting it to true in the web viewer ?  
(platform === "MacIntel" && maxTouchPoints > 1);
  const isIOSChrome = /CriOS/.test(userAgent);
  
  
  (function checkOnBlobSupport() {
    
    
    if (isIOSChrome) {
      compatibilityParams.disableCreateObjectURL = true;
    }
  })();
  
  
  (function checkCanvasSizeLimitation() {
    if (isIOS || isAndroid) {
      compatibilityParams.maxCanvasPixels = 5242880;
    }
  })();
}
const OptionKind = {
  VIEWER: 0x02,
  API: 0x04,
  WORKER: 0x08,
  PREFERENCE: 0x80,
};
/**
 * PLEASE NOTE: To avoid introducing unnecessary dependencies, we specify the
 *              values below *explicitly* rather than relying on imported types.
 */
const defaultOptions = {