Use channel in asyncFetch to handle different http status codes.
Add http test server response 204.
Make malformedURI test more specific and add unknown host and non-200 status tests.
Notify 'onManyLinksChanged' on every link fetch instead of on pref change.
Change test http handlers to be for prefixes instead of full paths.
Move getLocale() into DirectoryLinksProvider so it can be easily accessed within tests.
Add locale to http channel URIs and test that all server requests contain locale.
Use more descriptive property name.
Exclude error code from test condition.
Remove unnecessary helper function.
Remove unnecessary cleaning code.
Call onManyLinksChanged when directory file is written.
(into bug986521) Bug 993901 - Implement logic to decide when to fetch remotely hosted links
Introduce browser.newtabpage.directory prefix for directory preferences.
Implement directory download and timestamping.
Force directory download on directory source URL preference change.
Attempt directory download on newtab load if sponsored links are shown.
Download directory on init.