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.pdfViewer.currentPageNumber;
  },
  set page(val) {
    this.pdfViewer.currentPageNumber = val;
  },
  get supportsPrinting() {
    return PDFPrintServiceFactory.instance.supportsPrinting;
  },
  get supportsFullscreen() {
    if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
      return shadow(this, "supportsFullscreen", document.fullscreenEnabled);
    }
    const doc = document.documentElement;
    let support = !!(
      doc.requestFullscreen ||
      doc.mozRequestFullScreen ||
      doc.webkitRequestFullScreen
    );
    if (
      document.fullscreenEnabled === false ||
      document.mozFullScreenEnabled === false ||
      document.webkitFullscreenEnabled === false
    ) {
      support = false;
    }
    return shadow(this, "supportsFullscreen", support);
  },
  get supportsIntegratedFind() {