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)

return (this._jsActionsPromise ||= this._transport.getPageJSActions(
      this._pageIndex
    ));
  }
  /**
   * @returns {Promise<Object | null>} A promise that is resolved with
   *   an {Object} with a fake DOM object (a tree structure where elements
   *   are {Object} with a name, attributes (class, style, ...), value and
   *   children, very similar to a HTML DOM tree), or `null` if no XFA exists.
   */
  getXfa() {
    return (this._xfaPromise ||= this._transport.getPageXfa(this._pageIndex));
  }
  /**
   * Begins the process of rendering a page to the desired context.
   *
   * @param {RenderParameters} params Page render parameters.
   * @returns {RenderTask} An object that contains a promise that is
   *   resolved when the page finishes rendering.
   */
  render({