[NTP Snippets] Refactor background scheduling for remote suggestions

components/ntp_snippets/remote/remote_suggestions_hard_scheduler.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_NTP_SNIPPETS_REMOTE_REMOTE_SUGGESTIONS_HARD_SCHEDULER_H_
 #define COMPONENTS_NTP_SNIPPETS_REMOTE_REMOTE_SUGGESTIONS_HARD_SCHEDULER_H_
 
 #include "base/macros.h"
 #include "base/time/time.h"
 
 namespace ntp_snippets {
 
 // Interface to schedule "hard" periodic fetches of snippets. These "hard"
 // fetches must get triggered according to their schedule independent of whether
 // Chrome is running at that moment.
 class RemoteSuggestionsHardScheduler {

[Marc Treib, 2016/12/09 12:25:26]

I'm not very happy with this name. For one, "hard" is very clear. But more
importantly, this name sounds like it's "next to" RemoteSuggestionsScheduler,
maybe an alternative to it or something. But in fact, it's one level below, and
its responsibilities are very different (much more limited).

But I'm also not sure what a good name would be :)  Maybe something very
explicit like SchedulingOSBridge? That's really all it is.

[jkrcal, 2016/12/14 09:42:09]

What about PersistentScheduler?

[Marc Treib, 2016/12/14 10:47:01]

Hm. Certainly better than "hard", and since the new "scheduler" isn't actually
called "scheduler" anymore in the new design, I guess there's no risk of
confusion. So sure, SGTM!

  public:
   // Schedule periodic fetching of snippets, with different periods depending on
   // network state. Once per period, the concrete implementation should call
   // RemoteSuggestionsScheduler::Updater::HardUpdate() where the updater is
   // obtained from ContentSuggestionsService. Any of the periods can be zero to
   // indicate that the corresponding task should not be scheduled.
   virtual bool Schedule(base::TimeDelta period_wifi,
                         base::TimeDelta period_fallback) = 0;
 
-  // Cancel any scheduled tasks.
+  // Cancel any scheduled tasks. Equivalent to Schedule(0, 0).
   virtual bool Unschedule() = 0;
 
  protected:
   RemoteSuggestionsHardScheduler() = default;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(RemoteSuggestionsHardScheduler);
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_REMOTE_REMOTE_SUGGESTIONS_HARD_SCHEDULER_H_