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)

this._unblockDocumentLoadEvent();
    if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) {
      const { container } = this.appConfig.errorWrapper;
      container.hidden = true;
    }
    if (!this.pdfLoadingTask) {
      return;
    }
    if (
      (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
      this.pdfDocument?.annotationStorage.size > 0 &&
      this._annotationStorageModified
    ) {
      try {
        
        await this.save({ sourceEventType: "save" });
      } catch (reason) {
        
      }
    }
    const promises = [];
    promises.push(this.pdfLoadingTask.destroy());
    this.pdfLoadingTask = null;
    if (this.pdfDocument) {
      this.pdfDocument = null;
      this.pdfThumbnailViewer.setDocument(null);
      this.pdfViewer.setDocument(null);
      this.pdfLinkService.setDocument(null);
      this.pdfDocumentProperties.setDocument(null);
    }