Code review comment for lp:~yuningdodo/usb-creator/usb-creator.lp978691v2-select-readded-source

FYI, this patch is basically based on a previous patch for utopic:
https://code.launchpad.net/~yuningdodo/usb-creator/usb-creator.lp978691-select-readded-source/+merge/238286

I have tested it with the vivid daily image (20150306), it works as expected except the scrolling.