See https://bugzilla.mozilla.org/show_bug.cgi?id=1735738 for reference.
let failure = "";
      this._cleanup().then(() => {
        if (this.currentTask === this.manifest.length) {
          this._done();
          return;
        }
        const task = this.manifest[this.currentTask];
        task.round = 0;
        task.pageNum = task.firstPage || 1;
        task.stats = { times: [] };
        task.enableXfa = task.enableXfa === true;
        
        
        if (task.type === "other") {
          this._log(`Skipping file "${task.file}"\n`);
          if (!task.link) {
            this._nextPage(task, 'Expected "other" test-case to be linked.');
            return;
          }
          this.currentTask++;
          this._nextTask();
          return;
        }
        this._log('Loading file "' + task.file + '"\n');
        const absoluteUrl = new URL(task.file, window.location).href;
        try {
          let xfaStyleElement = null;