Well I managed to retrieve listen.pls from web radio that I wanted to listen via Chrome, so that I can listen to it on VLC so I got my problem solved (at least for volume).
But cause I still wanna find the solution for others, I did try you new solution.
So....
I get this ''unable to set'' for process name as well yes.
This last code is not working as well. I'm getting ivn stranger msg:
Unable to toggle application mute
If I choose mute insted of toggle mute, then I don't get any errors, but it doesn't mute the chrome
.