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.zoomLayer) {
      return;
    }
    const zoomLayerCanvas = this.zoomLayer.firstChild;
    this.paintedViewportMap.delete(zoomLayerCanvas);
    
    
    zoomLayerCanvas.width = 0;
    zoomLayerCanvas.height = 0;
    if (removeFromDOM) {
      
      this.zoomLayer.remove();
    }
    this.zoomLayer = null;
  }
  reset(keepZoomLayer = false, keepAnnotations = false) {