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.pdfRenderingQueue.printing = !!this.printService;
    this.pdfRenderingQueue.isThumbnailViewEnabled = this.pdfSidebar.isThumbnailViewVisible;
    this.pdfRenderingQueue.renderHighestPriority();
  },
  beforePrint() {
    
    
    this.pdfScriptingManager.dispatchWillPrint();
    if (this.printService) {
      
      
      
      return;
    }
    if (!this.supportsPrinting) {
      this.l10n.get("printing_not_supported").then(msg => {
        this._otherError(msg);
      });
      return;
    }