reason property indicates what kind of change was made to the contact.
var reason = instanceOfMozContactChangeEvent.reason
Return a string. Possible value is one of
The Contacts Manager API defines the properties
removed instead of the
|Feature||Chrome||Firefox (Gecko)||Internet Explorer||Opera||Safari|
|basic support||No support||No support||No support||No support||No support|
|Feature||Android||Chrome for Android||Firefox OS (Gecko)||IE Mobile||Opera Mobile||Safari Mobile|
|basic support||No support||No support||1.0.1||No support||No support||No support|
 As the specification is unstable, the Gecko implementation is completely non-standard.