AU: Simplify the automatic update check code a little.

update_attempter.h

Index: update_attempter.h
diff --git a/update_attempter.h b/update_attempter.h
index b2ef3719fa37cf7de85bdb3399153aff60d38d13..1c9ad40577791b52cbf3f9a7050936ba8f893e42 100644
--- a/update_attempter.h
+++ b/update_attempter.h
@@ -88,6 +88,13 @@ class UpdateAttempter : public ActionProcessorDelegate,
   // UPDATED_NEED_REBOOT. Returns true on sucess, false otherwise.
   bool RebootIfNeeded();
 
+  // Kicks off the periodic update checks, if necessary.
+  void InitiatePeriodicUpdateChecks();
+
+  // Schedules the next periodic update check |seconds| from now. Note
+  // that the actual timeout will be fuzzed.
+  void SchedulePeriodicUpdateCheck(int seconds);
+
   // DownloadActionDelegate methods
   void SetDownloadStatus(bool active);
   void BytesReceived(uint64_t bytes_received, uint64_t total);