We need to tell Android about preferred intervals, update the interval on failure and to respect Retry-After, perhaps adapt based on behavior, etc. See the FxAccountSyncAdapter code for inspiration. We also need to evaluate and tweak event-driven syncs: reads and writes of the ReadingListProvider should trigger rate-limited syncs, perhaps with an awareness of upload versus download (a distinction we could never make for Firefox Sync, but which works well for RL). For example, when loading the reading list home panel, we can check for new items to download, without bothering to upload status changes. When leaving the browser we can upload status changes. When adding a new item we can upload new items. Some of this might come for free as part of the intent bundle we get for a system-triggered sync. Take a look!

rnewman: how do you feel about this? This isn't cracking the whole nut; it's just making sure that we try to sync periodically. Changing the CountDownLatch for a BlockingQueue allows us to avoid threading state into delegates; it seems reasonable...

Comment on attachment 8584885 [details] Link to Github pull-request: https://github.com/mozilla-services/android-sync/pull/546 This makes me happy.

Comment on attachment 8584885 [details] Link to Github pull-request: https://github.com/mozilla-services/android-sync/pull/546 Batch uplift of Android RL to 38.