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)

font.data = null;
              }
              this.commonObjs.resolve(id, font);
            });
          break;
        case "FontPath":
        case "Image":
          this.commonObjs.resolve(id, exportedData);
          break;
        default:
          throw new Error(`Got unknown common object type ${type}`);
      }
    });
    messageHandler.on("obj", data => {
      if (this.destroyed) {
        
        return undefined;
      }
      const [id, pageIndex, type, imageData] = data;
      const pageProxy = this.pageCache[pageIndex];
      if (pageProxy.objs.has(id)) {
        return undefined;
      }
      switch (type) {
        case "Image":
          pageProxy.objs.resolve(id, imageData);