Bug 958900 - Pre: correct comment.
Bug 958900 - Pre: fix JavaDoc.
Bug 958900 - Part 1: extract (Prefs)BackoffHandler from Sync 1.1 SyncAdapter.
Bug 958900 - Part 2: rename shouldBackOff to shouldBackOffStorage.
Bug 958900 - Part 3: add SchedulePolicy interface for adjusting how FxAccountSyncAdapter will sync.
Bug 958900 - Part 4: implement backoff and periodic sync scheduling for FxAccountSyncAdapter.
Review comment: simplify PrefsBackoffHandler constructor, standardize on implicit leading dot in PrefsBackoffHandler path.
Review comment: lift shouldSync into the SyncAdapters.
Bug 958900 - Part 5: fix client count handling.
Post-test: correct token server backoff handling.
Post-test: add onlyExtend argument to SchedulePolicy.configureBackoffMillisOnBackoff.
Post-test: add logging about storage server changes.
Post-test: delay creation of schedulePolicy object.
Post-test: commenting.
Bug 972613 - In-memory sync rate limiting.
Bug 958900 - Implement scheduling and backoff for FxA Sync on Android. r=nalexander
Bug 972613 - In-memory sync rate limiting. r=trivial