I use https://chrome.google.com/webstore/detail/lastfm-scrobbler/hhinaapppaileiechjoiifaancjggfjm https://chrome.google.com/webstore/detail/lastfm-scrobbler/h..

I use https://chrome.google.com/webstore/detail/lastfm-scrobbler/hhinaapppaileiechjoiifaancjggfjm https://chrome.google.com/webstore/detail/lastfm-scrobbler/h... which supports GM, Pandora, etc.