Bug 1027995 - [User story] Transfer ringtones from SD card to ringtones folder

WIP
If the lifetime of the blob: urls is only as long as the Manage Ringtones screen is displayed, it seems fine to just hold on to them and have them die when the activity exits. But if the Manage Ringtones app has a longer lifetime, then I suppose this could be problematic.

Anyway, I agree that you probably don't need to worry about this here.