Last.fm Scrobbler for Chrome was created for people who listen to music online through their browser, and would like to keep an updated playback history using last.fm's scrobbling service.
You can get the scrobbler either from webstore directly or get the source code and enable "Developer mode" on Chrome
You can get it directly from Chrome Webstore: https://chrome.google.com/webstore/detail/lastfm-scrobbler/hhinaapppaileiechjoiifaancjggfjm
You can get the source code by cloning the repository. Then you need to enable "Developer mode" on your Chrome based browser and "Load unpacked extension".
Check the wiki pages to understand development of connectors.