Chrome Demo open API

How does the Chrome Demo work? When I open the index.html file nothing happens, am I suppose to do something special? All it says is: "

Welcome to Yeelight LED Demo App!

This app will discover Yeelight LED automatically. You can select the LED you want to control and send command to it. Try following commands, for more commands, please refer to Yeelight inter-operation spec.

_{“id”:1,“method”:“toggle”,“params”:[]} _
_{“id”:2,“method”:“set_bright”,“params”:[100]} _

Unzip the demo file to some folder.
Type “chrome://extensions/” in your chrome.

Enable dev mode, load extension, enable Yeelight demo, click start.

I did that but no option to connect to bulb or anything, as you can see on screenshot.
I opened console for background page of the extension and found this errors:

Error in response to socket.recvFrom: Error: Invocation of form socket.destroy(undefined) doesn't match definition socket.destroy(integer socketId)
    at ControlClient.mc_proto.disconnect (chrome-extension://efdmdjobaakoeidcjkdceaclkhkedgib/MulticastSocket.js:61:17)
    at Object.callback (chrome-extension://efdmdjobaakoeidcjkdceaclkhkedgib/MulticastSocket.js:83:12)
    at ControlClient.mc_proto._poll (chrome-extension://efdmdjobaakoeidcjkdceaclkhkedgib/MulticastSocket.js:77:21)
    at Object.callback (chrome-extension://efdmdjobaakoeidcjkdceaclkhkedgib/MulticastSocket.js:80:12)