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 (!this._pageLabels) {
      return null;
    }
    const i = this._pageLabels.indexOf(label);
    if (i < 0) {
      return null;
    }
    return i + 1;
  }
  /**
   * @typedef ScrollPageIntoViewParameters
   * @property {number} pageNumber - The page number.
   * @property {Array} [destArray] - The original PDF destination array, in the
   *   format: <page-ref> </XYZ|/FitXXX> <args..>
   * @property {boolean} [allowNegativeOffset] - Allow negative page offsets.
   *   The default value is `false`.
   * @property {boolean} [ignoreDestinationZoom] - Ignore the zoom argument in
   *   the destination array. The default value is `false`.
   */
  /**
   * Scrolls page into view.
   * @param {ScrollPageIntoViewParameters} params
   */
  scrollPageIntoView({