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)

throw error;
      }
    };
    const paintTask =
      this.renderer === RendererType.SVG
        ? this.paintOnSvg(canvasWrapper)
        : this.paintOnCanvas(canvasWrapper);
    paintTask.onRenderContinue = renderContinueCallback;
    this.paintTask = paintTask;
    const resultPromise = paintTask.promise.then(
      () => {
        return finishPaintTask(null).then(() => {
          if (textLayer) {
            const readableStream = pdfPage.streamTextContent({
              normalizeWhitespace: true,
              includeMarkedContent: true,
            });
            textLayer.setTextContentStream(readableStream);
            textLayer.render();
          }
        });
      },
      function (reason) {
        return finishPaintTask(reason);
      }
    );
    if (this.annotationLayerFactory) {
      if (!this.annotationLayer) {
        this.annotationLayer = this.annotationLayerFactory.createAnnotationLayerBuilder(
          div,