I was wondering if WebGL is considered stable enough to be enabled by default. It makes some PDFs render much faster and it has been off by default for a while now, so we have had quite some time to test it.

If we decide to enable WebGL by default, we should not forget to update https://github.com/mozilla/pdf.js/blob/master/extensions/chromium/preferences_schema.json#L39 as well.

/cc @yurydelendik 
/cc @Snuffleupagus (because IIRC you were testing WebGL too)

};
    
    loadingTask.onUnsupportedFeature = this.fallback.bind(this);
    return loadingTask.promise.then(
      pdfDocument => {
        this.load(pdfDocument);
      },
      exception => {
        if (loadingTask !== this.pdfLoadingTask) {
          return undefined; 
        }
        let key = "loading_error";
        if (exception instanceof InvalidPDFException) {
          key = "invalid_file_error";
        } else if (exception instanceof MissingPDFException) {
          key = "missing_file_error";
        } else if (exception instanceof UnexpectedResponseException) {
          key = "unexpected_response_error";
        }
        return this.l10n.get(key).then(msg => {
          this._documentError(msg, { message: exception?.message });
          throw exception;
        });
      }
    );
  },
  /**
   * @private
   */
  _ensureDownloadComplete() {