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)

const file = originalUrl !== undefined ? { url, originalUrl } : url;
        const args = length !== undefined ? { length } : null;
        this.open(file, args);
      },
      onError: err => {
        this.l10n.get("loading_error").then(msg => {
          this._documentError(msg, err);
        });
      },
      onProgress: (loaded, total) => {
        this.progress(loaded / total);
      },
    });
  },
  setTitleUsingUrl(url = "") {
    this.url = url;
    this.baseUrl = url.split("#")[0];
    let title = getPdfFilenameFromUrl(url, "");
    if (!title) {
      try {
        title = decodeURIComponent(getFilenameFromUrl(url)) || url;
      } catch (ex) {
        
        
        title = url;
      }
    }
    this.setTitle(title);
  },
  setTitle(title) {