Discount for inactivity timeout for recording session length

chrome/browser/metrics/desktop_engagement/desktop_engagement_service_unittest.cc

Index: chrome/browser/metrics/desktop_engagement/desktop_engagement_service_unittest.cc
diff --git a/chrome/browser/metrics/desktop_engagement/desktop_engagement_service_unittest.cc b/chrome/browser/metrics/desktop_engagement/desktop_engagement_service_unittest.cc
index 4670e22f60092f77f8783393827f68f09cfc08d8..a041fa6dc106771df5be1fd13c44f12770ff7a71 100644
--- a/chrome/browser/metrics/desktop_engagement/desktop_engagement_service_unittest.cc
+++ b/chrome/browser/metrics/desktop_engagement/desktop_engagement_service_unittest.cc
@@ -147,3 +147,26 @@ TEST(DesktopEngagementServiceTest, TestAudioEvent) {
   EXPECT_FALSE(instance.is_audio_playing());
   histogram_tester.ExpectTotalCount("Session.TotalDuration", 1);
 }
+
+TEST(DesktopEngagementServiceTest, TestTimeoutDiscount) {
+  base::MessageLoop loop(base::MessageLoop::TYPE_DEFAULT);
+  base::HistogramTester histogram_tester;
+
+  MockDesktopEngagementService instance;
+  instance.SetInactivityTimeoutForTesting(2);
+
+  instance.OnVisibilityChanged(true);
+  instance.OnUserEvent();
+  histogram_tester.ExpectTotalCount("Session.TotalDuration", 0);
+
+  // Wait until the session expires.
+  while (!instance.is_timeout()) {
+    base::RunLoop().RunUntilIdle();
+  }
+
+  histogram_tester.ExpectTotalCount("Session.TotalDuration", 1);
+
+  // The recorded value should be in the 0 bucket even though inactivity timeout
+  // is 2 seconds.
+  histogram_tester.ExpectUniqueSample("Session.TotalDuration", 0, 1);

[gayane -on leave until 09-2017, 2016/09/13 18:13:53]

this check appeared to be flaky and I assumed that maybe sometimes the session
length jumps from 0 to 1.

+}