Expose a method in VariationsService to trigger a seed fetch.

chrome/browser/metrics/variations/variations_request_scheduler_mobile_unittest.cc

+// Copyright 2014 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.
+
+#include "chrome/browser/metrics/variations/variations_request_scheduler_mobile.h"
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+#include "base/prefs/pref_registry_simple.h"
+#include "base/prefs/testing_pref_service.h"
+#include "chrome/common/pref_names.h"
+#include "testing/gtest/include/gtest/gtest.h"
+

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

Nit: Remove extra blank line.

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

Done.

+
+namespace chrome_variations {
+
+namespace {
+
+// Simple method used to verify a Callback has been triggered.
+void Increment(int *n) {
+  (*n)++;
+}
+
+}  // namespace
+
+TEST(VariationsRequestSchedulerMobileTest, StartNoRun) {
+  TestingPrefServiceSimple prefs;
+  // Initialize to as if it was just fetched.
+  prefs.registry()->RegisterInt64Pref(prefs::kVariationsLastFetchTime,
+                                      base::Time::Now().ToInternalValue());
+  int executed = 0;
+  const base::Closure task = base::Bind(&Increment, &executed);
+  VariationsRequestSchedulerMobile scheduler(task, &prefs);
+  scheduler.Start();
+  // We expect it the task to not have triggered.
+  EXPECT_EQ(0, executed);
+}
+
+TEST(VariationsRequestSchedulerMobileTest, StartRun) {
+  TestingPrefServiceSimple prefs;
+  // Verify it doesn't take more than a day.
+  base::Time old = base::Time::Now() - base::TimeDelta::FromHours(24);
+  prefs.registry()->RegisterInt64Pref(prefs::kVariationsLastFetchTime,
+                                      old.ToInternalValue());
+  int executed = 0;
+  const base::Closure task = base::Bind(&Increment, &executed);
+  VariationsRequestSchedulerMobile scheduler(task, &prefs);
+  scheduler.Start();
+  // We expect the task to have triggered.
+  EXPECT_EQ(1, executed);
+}
+
+TEST(VariationsRequestSchedulerMobileTest, ScheduleFetch) {
+    base::MessageLoopForUI message_loop_;

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

Indent is wrong.

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

Done.

+
+  TestingPrefServiceSimple prefs;
+
+  base::Time old = base::Time::Now() - base::TimeDelta::FromHours(24);
+  prefs.registry()->RegisterInt64Pref(prefs::kVariationsLastFetchTime,
+                                      old.ToInternalValue());
+  int executed = 0;
+  const base::Closure task = base::Bind(&Increment, &executed);
+  VariationsRequestSchedulerMobile scheduler(task, &prefs);
+
+  // Verify timer not running.
+  EXPECT_FALSE(scheduler.schedule_fetch_timer_.IsRunning());
+  scheduler.ScheduleFetch();
+
+  // Timer now running.
+  EXPECT_TRUE(scheduler.schedule_fetch_timer_.IsRunning());
+
+  // Force execution of the task on this timer.

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

I'd expand the comment to say that this is verifying that the timer will run the
callback.

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

I didn't see a way to simulate time passing for a timer. What I test here is
that the timer is running, and then I force the task attached to the timer to be
triggered. This verifies that the timer does start, and that it has the correct
task associated.

[Alexei Svitkine (slow), 2014/02/13 17:36:22]

Right. I was just saying that you should expand the comment in the code to say
that.

[rkaplow, 2014/02/13 18:54:47]

Done.

+  scheduler.schedule_fetch_timer_.user_task().Run();
+
+  // We expect the input task to have triggered.
+  EXPECT_EQ(1, executed);
+}
+

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

Nit: Remove extra line.

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

Done.

+
+}  // namespace chrome_variations