Q: AirDrop disappeared from right-click 'Share' menu?

I'm running a MacBook Pro (non-retina) 13" 8GB 750GB MD102X/A.
After updating to OS X El Capitan, I've noticed that AirDrop is no longer listed in the right-click 'Share' menu.

The menu now displays Twitter, Facebook, Messages, Notes, More... (screenshot above), yet when I click more, a System Preferences - Extensions window appears providing me a list of different services I can share using (such as Vimeo, LinkedIn, Reminders, Weibo, etc.), but AirDrop is not listed.

When I search AirDrop in System Preferences it returns me to the Extensions settings (screenshot above), but again is not listed within the System Preferences window or the Right-click 'Share' menu.

AirDrop works perfectly in the Finder>AirDrop window, and my Mac sends/receives images fine with my iPhone. I'd just like to get AirDrop back to my Right-click 'Share' menu as it's one of the features I use almost everyday.

Thanks,

John