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.enablePrintAutoRotate = options.enablePrintAutoRotate || false;
    this.renderer = options.renderer || RendererType.CANVAS;
    this.enableWebGL = options.enableWebGL || false;
    this.useOnlyCssZoom = options.useOnlyCssZoom || false;
    this.maxCanvasPixels = options.maxCanvasPixels;
    this.l10n = options.l10n || NullL10n;
    this.enableScripting =
      options.enableScripting === true && !!this._scriptingManager;
    this.defaultRenderingQueue = !options.renderingQueue;
    if (this.defaultRenderingQueue) {
      
      this.renderingQueue = new PDFRenderingQueue();
      this.renderingQueue.setViewer(this);
    } else {
      this.renderingQueue = options.renderingQueue;
    }
    this.scroll = watchScroll(this.container, this._scrollUpdate.bind(this));
    this.presentationModeState = PresentationModeState.UNKNOWN;
    this._onBeforeDraw = this._onAfterDraw = null;
    this._resetView();
    if (this.removePageBorders) {
      this.viewer.classList.add("removePageBorders");
    }
    
    
    Promise.resolve().then(() => {
      this.eventBus.dispatch("baseviewerinit", { source: this });
    });
  }
  get pagesCount() {