[Offline Pages] Moves Coordinator to using MarkAttemptStarted/MarkAttemptCompleted API.

components/offline_pages/background/save_page_request.cc

Index: components/offline_pages/background/save_page_request.cc
diff --git a/components/offline_pages/background/save_page_request.cc b/components/offline_pages/background/save_page_request.cc
index f9372f340a47373ef44a7cb5940d925d810265e5..e5424d703611034e35a24bc1d32703e5aefb6915 100644
--- a/components/offline_pages/background/save_page_request.cc
+++ b/components/offline_pages/background/save_page_request.cc
@@ -78,4 +78,12 @@ void SavePageRequest::MarkAttemptCompleted() {
   last_attempt_time_ = base::Time();
 }
 
+void SavePageRequest::MarkAttemptAborted() {
+  DCHECK_GT(attempt_count_, 0);
+  last_attempt_time_ = base::Time();
+  // TODO(dougarnett): Would be safer if we had two persisted counters
+  // (attempts_started and attempts_completed) rather just one with decrement.
+  --attempt_count_;

[fgorski, 2016/08/04 06:01:34]

based on discussion we had today with pete, dimich and justin, we should
probably be incrementing attempt count upon unsuccessful completion that is
retriable, rather than before making an attempt. That prevents us from
decrementing on the abort.

[dougarnett, 2016/08/04 16:24:38]

So change MarkAttemptStarted and MarkAttemptCompleted then - in this CL?

Btw, I'm concerned that we have some way to stop processing requests that never
complete - that is, after they start, we always get swapped out or chrome
crashes. Did you guys discuss this type of situation? I had raised it with Pete
on Tuesday as a flaw with how he was currently doing the increment after attempt
completed.

[dougarnett, 2016/08/04 16:45:28]

Pondering a bit more, I think we should keep this as it is for this iteration. I
think it is better approach prior to add state variable or doing more work to
uses last attempt time to imply the in-progress state. I could add more text to
the above TODO but doesn't really seem necessary as another iteration planned in
near term.

+}
+
 }  // namespace offline_pages