Location Notifications - GPlus Provider for Chrome
More About Location Notifications - GPlus Provider
Guess what, Google moved location sharing from G+ back to GMaps again (Come on, can we please have some stability already? Location reporting is an infrastructural service, not a fashion business).
Anyway please install the new "Google Maps Location Provider" extension: https://chrome.google.com/webstore/detail/location-notifications-ex/aoiaobnnbepbkgepbccipipllpmoegjk