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)

renderer: AppOptions.get("renderer"),
      enableWebGL: AppOptions.get("enableWebGL"),
      l10n: this.l10n,
      textLayerMode: AppOptions.get("textLayerMode"),
      imageResourcesPath: AppOptions.get("imageResourcesPath"),
      renderInteractiveForms: AppOptions.get("renderInteractiveForms"),
      enablePrintAutoRotate: AppOptions.get("enablePrintAutoRotate"),
      useOnlyCssZoom: AppOptions.get("useOnlyCssZoom"),
      maxCanvasPixels: AppOptions.get("maxCanvasPixels"),
      enableScripting: AppOptions.get("enableScripting"),
    });
    pdfRenderingQueue.setViewer(this.pdfViewer);
    pdfLinkService.setViewer(this.pdfViewer);
    pdfScriptingManager.setViewer(this.pdfViewer);
    this.pdfThumbnailViewer = new PDFThumbnailViewer({
      container: appConfig.sidebar.thumbnailView,
      eventBus,
      renderingQueue: pdfRenderingQueue,
      linkService: pdfLinkService,
      l10n: this.l10n,
    });
    pdfRenderingQueue.setThumbnailViewer(this.pdfThumbnailViewer);
    this.pdfHistory = new PDFHistory({
      linkService: pdfLinkService,
      eventBus,
    });
    pdfLinkService.setHistory(this.pdfHistory);
    if (!this.supportsIntegratedFind) {
      this.findBar = new PDFFindBar(appConfig.findBar, eventBus, this.l10n);
    }