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)

if (
      (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
      arguments.length > 0
    ) {
      deprecated("saveDocument no longer accepts any options.");
    }
    if (
      (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
      this._transport.annotationStorage.size <= 0
    ) {
      deprecated(
        "saveDocument called while `annotationStorage` is empty, " +
          "please use the getData-method instead."
      );
    }
    return this._transport.saveDocument();
  }
  /**
   * @returns {Promise<Array<Object> | null>} A promise that is resolved with an
   *   {Array<Object>} containing /AcroForm field data for the JS sandbox,
   *   or `null` when no field data is present in the PDF file.
   */
  getFieldObjects() {
    return this._transport.getFieldObjects();
  }
  /**
   * @returns {Promise<boolean>} A promise that is resolved with `true`
   *   if some /AcroForm fields have JavaScript actions.
   */
  hasJSActions() {