Account-plugin-facebook, These plugins are responsible for creating and configuring online accounts. 

$ sudo apt-get update

$ sudo apt-get install account-plugin-facebook

Sample installation output,

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be upgraded:
1 upgraded, 0 newly installed, 0 to remove and 262 not upgraded.
2 not fully installed or removed.
Need to get 2,906 B of archives.
After this operation, 0 B of additional disk space will be used.
WARNING: The following packages cannot be authenticated!

account-plugin-facebook package information are,

distro        Ubuntu 14.04 (Trusty Tahr)
section        Main
name        account-plugin-facebook
version        0.11+14.04.20140409.1-0ubuntu1
description    GNOME Control Center account plugin for single signon - facebook