sync: make scheduling logic and job ownership more obvious.

sync/engine/sync_scheduler.h

Index: sync/engine/sync_scheduler.h
diff --git a/sync/engine/sync_scheduler.h b/sync/engine/sync_scheduler.h
index d251b98599378ba202ec3babf969037ff5998195..94a35b1464e3c2ed30471eb91a5dca93bfbe7bb6 100644
--- a/sync/engine/sync_scheduler.h
+++ b/sync/engine/sync_scheduler.h
@@ -85,6 +85,9 @@ class SyncScheduler : public sessions::SyncSession::Delegate {
 
   // The meat and potatoes. Both of these methods will post a delayed task
   // to attempt the actual nudge (see ScheduleNudgeImpl).
+  // NOTE: |delay| is best-effort. If a nudge is already scheduled to depart

[rlarocque, 2012/09/24 21:15:14]

Rename to max_delay?  I think that would make the effect clear without requiring
a comment.

[akalin, 2012/09/25 22:37:24]

but it's not a max delay, right?  the nudge can happen anytime after the delay
(due to the nature of timers, delayed tasks, etc.)

delay_hint?

[tim (not reviewing), 2012/10/08 00:20:03]

I renamed to desired_delay (following the base/timer.h desired_run_time pattern)
but I still think the comment is interesting. I added to it to mention the fact
that it may happen later as well, although that part is arguably "status quo"
when interacting with timers / delayed tasks in Chrome... but let me know what
you think.  If you prefer delay_hint, I'm fine with that too.

+  // earlier than Now() + delay, the scheduler can and will prefer to batch
+  // the two so that only one nudge is sent (at the earlier time).
   virtual void ScheduleNudgeAsync(
       const base::TimeDelta& delay,
       NudgeSource source,