Remove Airdrop function to do tightening of OSX
I did some looking around and came up with that the removing the AirDrop will give you only 150kb of space.

So I am not sure it is wort messing around with it, since I do not know what dependencies are there, and the disk space gain is not worth mentioning it.

You can look it up in your

/System/Library/PrivateFrameworks/ShareKit.framework/Versions/A/PlugIns/AirDrop.sharingservice/Contents/MacOS