Bug 1050097 - [Camera] Add error handling while |videoStorage.addNamed| occurs error.

I would return the error on the callback of this function instead of generating an event. You would have to change the place where this function is defined and called in js/camera/lib/camera.js (lines 1161 and 916). Unit tests will probably have to be fixed. You can run the unit tests by running ./bin/gaia-test in your gaia checkout directory