After version upgrade we must clear Snippets cache and re-fetch snippets. Atm we fetch snippets on every start but this will change in bug 1433243. After this change we want to force update on start only when Firefox has been upgraded.

hey kate, could you triage this? is it necessary?

For some reason we may target specific versions / builds with messaging (i.e. for upgrade). This has happened in the past and we built this functionality in about:home. Although we had a different targeting system then it still looks like a good practice.

Set it to block bug 1433243 so we implement the two together.

I'm not sure we're going to actually need bug 1433243 since we are in the main process now and especially if we switch to remote settings (since that would handle cacheing for us). However, if we do, this would definitely be important.