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.scale = scale || this.scale;
    
    if (typeof rotation !== "undefined") {
      this.rotation = rotation;
    }
    if (optionalContentConfigPromise instanceof Promise) {
      this._optionalContentConfigPromise = optionalContentConfigPromise;
    }
    const totalRotation = (this.rotation + this.pdfPageRotate) % 360;
    this.viewport = this.viewport.clone({
      scale: this.scale * CSS_UNITS,
      rotation: totalRotation,
    });
    if (this.svg) {
      this.cssTransform(this.svg, true);
      this.eventBus.dispatch("pagerendered", {
        source: this,
        pageNumber: this.id,
        cssTransform: true,
        timestamp: performance.now(),
        error: this._renderError,
      });
      return;
    }