[NTP Snippets] Scheduler: Fetch on Wifi (without charging) only 6AM-10PM

components/ntp_snippets/ntp_snippets_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_NTP_SNIPPETS_SCHEDULER_H_
 #define COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_SCHEDULER_H_
 
 #include "base/macros.h"
 #include "base/time/time.h"
 
 namespace ntp_snippets {
 
 // Interface to schedule the periodic fetching of snippets.
 class NTPSnippetsScheduler {
  public:
   // Schedule periodic fetching of snippets, with different period depending on
-  // network and charging state. The concrete implementation should call
-  // NTPSnippetsService::FetchSnippets once per period.
+  // network and charging state, and also set up a delay after which the periods
+  // may change. The concrete implementation should call
+  // NTPSnippetsService::FetchSnippets once per period, and
+  // NTPSnippetsService::RescheduleFetching at |reschedule_time|.
+  // Any of the values can be zero to indicate that the corresponding task
+  // should not be scheduled.
   virtual bool Schedule(base::TimeDelta period_wifi_charging,
                         base::TimeDelta period_wifi,
-                        base::TimeDelta period_fallback) = 0;
+                        base::TimeDelta period_fallback,
+                        base::Time reschedule_time) = 0;
 
-  // Cancel the scheduled fetching task, if any.
+  // Cancel any scheduled tasks.
   virtual bool Unschedule() = 0;
 
  protected:
   NTPSnippetsScheduler() = default;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(NTPSnippetsScheduler);
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_SCHEDULER_H_