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 sendTest = () => {
            const testObj = new Uint8Array([
              this.postMessageTransfers ? 255 : 0,
            ]);
            
            
            try {
              messageHandler.send("test", testObj, [testObj.buffer]);
            } catch (ex) {
              warn("Cannot use postMessage transfers.");
              testObj[0] = 0;
              messageHandler.send("test", testObj);
            }
          };
          
          
          
          
          sendTest();
          return;
        } catch (e) {
          info("The worker has been disabled.");
        }
      }
      
      
      this._setupFakeWorker();
    }
    _setupFakeWorker() {