[Background Sync] Add unit test for num_attempts

setting logic.

This updates a unit test and adds another to verify that we're setting
num_attempts as expected for Periodic Background Sync registrations.

Bug: 989444
Change-Id: Ic4aa69f772ce388025ad4344f346464813f679a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1729086
Commit-Queue: Mugdha Lakhani <nator@chromium.org>
Auto-Submit: Mugdha Lakhani <nator@chromium.org>
Reviewed-by: Rayan Kanso <rayankans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683228}

content/browser/background_sync/background_sync_manager_unittest.cc

@@ -1221,20 +1221,28 @@ TEST_F(BackgroundSyncManagerTest, FiresOnRegistration) {
 
 TEST_F(BackgroundSyncManagerTest, PeriodicSyncFiresWhenExpected) {
   InitPeriodicSyncEventTest();
-  int thirteen_hours_ms = 13 * 60 * 60 * 1000;
-  sync_options_2_.min_interval = thirteen_hours_ms;
+  base::TimeDelta thirteen_hours = base::TimeDelta::FromHours(13);
+  sync_options_2_.min_interval = thirteen_hours.InMilliseconds();
 
   EXPECT_TRUE(Register(sync_options_2_));
   EXPECT_EQ(0, periodic_sync_events_called_);
   EXPECT_TRUE(GetRegistration(sync_options_2_));
 
   // Advance clock.
-  test_clock_.Advance(base::TimeDelta::FromMilliseconds(thirteen_hours_ms));
+  test_clock_.Advance(thirteen_hours);
   FireReadyEvents();
   base::RunLoop().RunUntilIdle();
 
   EXPECT_EQ(1, periodic_sync_events_called_);
   EXPECT_TRUE(GetRegistration(sync_options_2_));
+
+  // Advance clock again.
+  test_clock_.Advance(thirteen_hours);
+  FireReadyEvents();
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_EQ(2, periodic_sync_events_called_);
+  EXPECT_TRUE(GetRegistration(sync_options_2_));
 }
 
 TEST_F(BackgroundSyncManagerTest, TestSupensionAndRevival) {
@@ -1855,6 +1863,53 @@ TEST_F(BackgroundSyncManagerTest, OneAttempt) {
   EXPECT_FALSE(GetRegistration(sync_options_1_));
 }
 
+TEST_F(BackgroundSyncManagerTest, TwoFailedAttemptsForPeriodicSync) {
+  SetMaxSyncAttemptsAndRestartManager(2);
+  InitFailedPeriodicSyncEventTest();
+
+  base::TimeDelta thirteen_hours = base::TimeDelta::FromHours(13);
+  sync_options_2_.min_interval = thirteen_hours.InMilliseconds();
+
+  EXPECT_TRUE(Register(sync_options_2_));
+  EXPECT_TRUE(GetRegistration(sync_options_2_));
+  EXPECT_EQ(0, periodic_sync_events_called_);
+
+  // Advance clock.
+  test_clock_.Advance(thirteen_hours);
+  FireReadyEvents();
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_EQ(1, periodic_sync_events_called_);
+  EXPECT_TRUE(GetRegistration(sync_options_2_));
+
+  // Since this one failed, a wakeup/delayed task will be scheduled for retries
+  // after five minutes.
+  EXPECT_EQ(base::TimeDelta::FromMinutes(5),
+            test_background_sync_manager()->delayed_periodic_sync_task_delta());
+  test_clock_.Advance(base::TimeDelta::FromMinutes(5));
+  FireReadyEvents();
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_EQ(2, periodic_sync_events_called_);
+  EXPECT_TRUE(GetRegistration(sync_options_2_));
+
+  // Second attempt would also fail, resetting to next thirteen_hours.
+  // Expect nothing after just another hour.
+  test_clock_.Advance(base::TimeDelta::FromHours(1));
+  FireReadyEvents();
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_EQ(2, periodic_sync_events_called_);
+
+  // Expect the next event after another twelve hours.
+  test_clock_.Advance(base::TimeDelta::FromHours(12));
+  FireReadyEvents();
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_EQ(3, periodic_sync_events_called_);
+  EXPECT_TRUE(GetRegistration(sync_options_2_));
+}
+
 TEST_F(BackgroundSyncManagerTest, TwoAttempts) {
   SetMaxSyncAttemptsAndRestartManager(2);
   InitFailedSyncEventTest();