There are two parts to this change. The first is a module to drive kinto
collection sync. This gives server-provided last-update times to each module
managing collection information so that data is only fetched when updates are
necessary. This also keeps track of when pings last took place (for future use)
and any apparent difference between client and server clock (we need this later
for the content signing work).
Currently only one module (the kinto version of the OneCRL client) consumes this
information, though more will follow.
The second is a minor change to nsBlocklistService.js to ensure that this ping
takes place whenever the existing blocklist ping happens.
MozReview-Commit-ID: 7SN03AOJ4Wc
985802557a