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)

/**
   * @param {PDFViewerOptions} options
   */
  constructor(options) {
    if (this.constructor === BaseViewer) {
      throw new Error("Cannot initialize BaseViewer.");
    }
    const viewerVersion =
      typeof PDFJSDev !== "undefined" ? PDFJSDev.eval("BUNDLE_VERSION") : null;
    if (version !== viewerVersion) {
      throw new Error(
        `The API version "${version}" does not match the Viewer version "${viewerVersion}".`
      );
    }
    this._name = this.constructor.name;
    this.container = options.container;
    this.viewer = options.viewer || options.container.firstElementChild;