Anshul, I've been taking a look a this. At jaoo@68ffdd8fd7961e8c48520d6004dd169c0eaafc25 I managed to reproduce the issue somehow. I added a test case in which the mozIcc object is remove and I hit the issue you commented. The fix you added LGTM since if the mozIcc object is removed is safe to skip the removing of the event listeners as the object is not available anymore. I've run the unit test and everything seem correct. Also I tested this on a device and everything is working fine. To sum up, would you be OK with landing the patch I did since it has the unit testing part?