There is no reason why we would need two separate files here. Lets combine both into a single file called scraper.py.
Further I would also suggest that we update the class name of the base class to have the correct API right away before releasing to pypi:
MozillaScraper => Scraper
The other classes look fine and wouldn't need an update.
Combine mozdownload.py and scraper.py into a single file. Fixes issue #2