Expose a method in VariationsService to trigger a seed fetch.

chrome/browser/metrics/variations/variations_request_scheduler.h

 // Copyright (c) 2013 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 CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_REQUEST_SCHEDULER_H_
 #define CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_REQUEST_SCHEDULER_H_
 
 #include "base/bind.h"
 #include "base/gtest_prod_util.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 
 class PrefService;
 
 namespace chrome_variations {
 
 // A helper class that makes VariationsService requests at the correct times.
 class VariationsRequestScheduler {
  public:
   virtual ~VariationsRequestScheduler();
 
-  // Starts the task on a schedule.
+  // Starts the task. This can be a repeated event or a one-off.
   virtual void Start();
 
   // Resets the scheduler if it is currently on a timer.
   virtual void Reset();
 
   // Schedules a fetch shortly, for example to re-try the initial request which
   // may have failed.
-  void ScheduleFetchShortly();
+  void ForceFetch();

[Alexei Svitkine (slow), 2014/02/13 16:13:08]

Why did you rename this? I found the previous name more intuitive (since Force
sounds like it may be immediately, whereas the other name suggests there will be
a delay).

[rkaplow, 2014/02/13 16:55:59]

Renaming was required when I had ScheduleFetch named based on what it was doing,
and it seemed the clearest way to differentiate the two. If we're switching the
other to OnApp then I can leave this as it was.

+
+  // Potentially fetch a new seed, depending on implementation. This may only
+  // fetch if there has not been one recently.
+  virtual void ScheduleFetch();

[Alexei Svitkine (slow), 2014/02/13 16:13:08]

Actually, I'd prefer if this was also named OnAppEnterForeground().

The idea is that in the eventual refactoring, we'd want this object to listen
for the events, and VariationsService to have no knowledge of it.

[rkaplow, 2014/02/13 16:55:59]

Done.

 
   // Factory method for this class.
   static VariationsRequestScheduler* Create(const base::Closure& task,
                                             PrefService* local_state);
 
  protected:
   // |task| is the closure to call when the scheduler deems ready.
   explicit VariationsRequestScheduler(const base::Closure& task);
 
   // Getter for derived classes.
   base::Closure task() const;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(VariationsRequestSchedulerTest,
-                           ScheduleFetchShortly);
+                           ForceFetch);
 
   // The task scheduled by this class.
   base::Closure task_;
 
   // The timer used to repeatedly ping the server. Keep this as an instance
   // member so if VariationsRequestScheduler goes out of scope, the timer is
   // automatically canceled.
   base::RepeatingTimer<VariationsRequestScheduler> timer_;
 
   // A one-shot timer used for scheduling out-of-band fetches.
   base::OneShotTimer<VariationsRequestScheduler> one_shot_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(VariationsRequestScheduler);
 };
 
 }  // namespace chrome_variations
 
 #endif  // CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_REQUEST_SCHEDULER_H_