Media Engagement: use min required visits for MEI score when visits is too low.

This is allowing us to compute a MEI score during the warm up period
and cut down the warmup period if we know that the score would at worse
already be high enough.

For example, with minimum visits at 10 and MEI threshold at 3, after 3
visits with playback, a website could get MEI privilege instead of
waiting for the 7 following visits.

Bug: 807268
Change-Id: Id5f65f2d97375ed7507b99925459ab11139c2ae4
Reviewed-on: https://chromium-review.googlesource.com/893263Reviewed-by: Tommy Steimel <steimel@chromium.org>
Commit-Queue: Mounir Lamouri (slow) <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532891}

chrome/browser/media/media_engagement_contents_observer_unittest.cc

@@ -674,7 +674,7 @@ TEST_F(MediaEngagementContentsObserverTest, InteractionsRecorded) {
   Navigate(url);
   SimulateAudible();
   SimulateSignificantPlaybackTimeForPage();
-  ExpectScores(url, 0.0, 2, 1, 0, 0);
+  ExpectScores(url, 0.05, 2, 1, 0, 0);
 }
 
 TEST_F(MediaEngagementContentsObserverTest,
@@ -734,7 +734,7 @@ TEST_F(MediaEngagementContentsObserverTest, RecordScoreOnPlayback) {
   Navigate(url3);
   SimulateAudioVideoPlaybackStarted(0);
   tester.ExpectBucketCount(
-      MediaEngagementContentsObserver::kHistogramScoreAtPlaybackName, 0, 1);
+      MediaEngagementContentsObserver::kHistogramScoreAtPlaybackName, 20, 1);
   tester.ExpectTotalCount(
       MediaEngagementContentsObserver::kHistogramScoreAtPlaybackName, 4);
 
@@ -915,11 +915,11 @@ TEST_F(MediaEngagementContentsObserverTest, RecordAudiblePlayers_OnDestroy) {
   SimulateSignificantPlaybackTimeForPlayer(0);
   SimulateSignificantPlaybackTimeForPlayer(1);
   SimulateSignificantPlaybackTimeForPlayer(2);
-  ExpectScores(url, 0, 1, 1, 0, 0);
+  ExpectScores(url, 0.05, 1, 1, 0, 0);
 
   // Test that when we destroy the audible players the scores are recorded.
   SimulateDestroy();
-  ExpectScores(url, 0, 1, 1, 3, 3);
+  ExpectScores(url, 0.05, 1, 1, 3, 3);
 }
 
 TEST_F(MediaEngagementContentsObserverTest, RecordAudiblePlayers_OnNavigate) {
@@ -947,18 +947,18 @@ TEST_F(MediaEngagementContentsObserverTest, RecordAudiblePlayers_OnNavigate) {
   SimulateSignificantPlaybackTimeForPlayer(0);
   SimulateSignificantPlaybackTimeForPlayer(1);
   SimulateSignificantPlaybackTimeForPlayer(2);
-  ExpectScores(url, 0, 1, 1, 0, 0);
+  ExpectScores(url, 0.05, 1, 1, 0, 0);
 
   // Navigate to a sub page and continue watching.
   Navigate(GURL("https://www.google.com/test"));
   SimulateSignificantAudioPlayer(1);
   SimulateLongMediaPlayback(1);
-  ExpectScores(url, 0, 1, 1, 0, 0);
+  ExpectScores(url, 0.05, 1, 1, 0, 0);
 
   // Test that when we navigate to a new origin the audible players the scores
   // are recorded.
   Navigate(GURL("https://www.google.co.uk"));
-  ExpectScores(url, 0, 1, 1, 4, 3);
+  ExpectScores(url, 0.05, 1, 1, 4, 3);
 }
 
 TEST_F(MediaEngagementContentsObserverTest, TimerSpecificToPlayer) {

chrome/browser/media/media_engagement_score.cc

@@ -201,12 +201,10 @@ bool MediaEngagementScore::UpdateScoreDict() {
 }
 
 void MediaEngagementScore::Recalculate() {
-  // Update the engagement score.
-  actual_score_ = 0;
-  if (visits() >= GetScoreMinVisits()) {
-    actual_score_ =
-        static_cast<double>(media_playbacks()) / static_cast<double>(visits());
-  }
+  // Use the minimum visits to compute the score to allow websites that would
+  // surely have a high MEI to pass the bar early.
+  double effective_visits = std::max(visits(), GetScoreMinVisits());
+  actual_score_ = static_cast<double>(media_playbacks()) / effective_visits;
 
   // Recalculate whether the engagement score is considered high.
   if (is_high_) {

chrome/browser/media/media_engagement_score_unittest.cc

@@ -343,10 +343,9 @@ TEST_F(MediaEngagementScoreTest, EngagementScoreCalculation) {
   EXPECT_EQ(0, score_->actual_score());
   UpdateScore(score_);
 
-  // Check that the score is zero even with 1 visit.
-  EXPECT_EQ(0.0, score_->actual_score());
+  // Check that the score increases when there is one visit.
+  EXPECT_EQ(0.05, score_->actual_score());
 
-  EXPECT_EQ(0, score_->actual_score());
   SetScore(20, 8);
   EXPECT_EQ(0.4, score_->actual_score());
 
@@ -429,9 +428,9 @@ TEST_F(MediaEngagementScoreTest, OverrideFieldTrial) {
   EXPECT_FALSE(score_->high_score());
   EXPECT_EQ(0.85, MediaEngagementScore::GetHighScoreLowerThreshold());
 
-  // Raise the minimum visits, the score will now be zero as it does not meet
-  // the threshold requirements.
+  // Raise the minimum visits, the score will now be relative to this new
+  // visits requirements.
   OverrideFieldTrial(25, 0.85, 0.9);
-  EXPECT_EQ(0.0, score_->actual_score());
+  EXPECT_EQ(0.64, score_->actual_score());
   EXPECT_EQ(25, MediaEngagementScore::GetScoreMinVisits());
 }

chrome/browser/media/media_engagement_service_unittest.cc

@@ -259,19 +259,19 @@ TEST_F(MediaEngagementServiceTest,
   GURL url1("https://www.google.com");
   ExpectScores(url1, 0.0, 0, 0, TimeNotSet());
   RecordVisitAndPlaybackAndAdvanceClock(url1);
-  ExpectScores(url1, 0.0, 1, 1, Now());
+  ExpectScores(url1, 0.05, 1, 1, Now());
 
   RecordVisit(url1);
-  ExpectScores(url1, 0.0, 2, 1, Now());
+  ExpectScores(url1, 0.05, 2, 1, Now());
 
   RecordPlayback(url1);
-  ExpectScores(url1, 0.0, 2, 2, Now());
+  ExpectScores(url1, 0.1, 2, 2, Now());
   base::Time url1_time = Now();
 
   GURL url2("https://www.google.co.uk");
   RecordVisitAndPlaybackAndAdvanceClock(url2);
-  ExpectScores(url2, 0.0, 1, 1, Now());
-  ExpectScores(url1, 0.0, 2, 2, url1_time);
+  ExpectScores(url2, 0.05, 1, 1, Now());
+  ExpectScores(url1, 0.1, 2, 2, url1_time);
 }
 
 TEST_F(MediaEngagementServiceTest, IncognitoEngagementService) {
@@ -286,8 +286,8 @@ TEST_F(MediaEngagementServiceTest, IncognitoEngagementService) {
 
   MediaEngagementService* incognito_service =
       MediaEngagementService::Get(profile()->GetOffTheRecordProfile());
-  ExpectScores(incognito_service, url1, 0.0, 1, 1, url1_time);
-  ExpectScores(incognito_service, url2, 0.0, 1, 1, Now());
+  ExpectScores(incognito_service, url1, 0.05, 1, 1, url1_time);
+  ExpectScores(incognito_service, url2, 0.05, 1, 1, Now());
   ExpectScores(incognito_service, url3, 0.0, 0, 0, TimeNotSet());
 
   incognito_service->RecordVisit(url3);
@@ -295,17 +295,17 @@ TEST_F(MediaEngagementServiceTest, IncognitoEngagementService) {
   ExpectScores(url3, 0.0, 0, 0, TimeNotSet());
 
   incognito_service->RecordVisit(url2);
-  ExpectScores(incognito_service, url2, 0.0, 2, 1, Now());
-  ExpectScores(url2, 0.0, 1, 1, Now());
+  ExpectScores(incognito_service, url2, 0.05, 2, 1, Now());
+  ExpectScores(url2, 0.05, 1, 1, Now());
 
   RecordVisitAndPlaybackAndAdvanceClock(url3);
   ExpectScores(incognito_service, url3, 0.0, 1, 0, TimeNotSet());
-  ExpectScores(url3, 0.0, 1, 1, Now());
+  ExpectScores(url3, 0.05, 1, 1, Now());
 
   ExpectScores(incognito_service, url4, 0.0, 0, 0, TimeNotSet());
   RecordVisitAndPlaybackAndAdvanceClock(url4);
-  ExpectScores(incognito_service, url4, 0.0, 1, 1, Now());
-  ExpectScores(url4, 0.0, 1, 1, Now());
+  ExpectScores(incognito_service, url4, 0.05, 1, 1, Now());
+  ExpectScores(url4, 0.05, 1, 1, Now());
 }
 
 TEST_F(MediaEngagementServiceTest, IncognitoOverrideRegularProfile) {
@@ -368,7 +368,7 @@ TEST_F(MediaEngagementServiceTest, IncognitoOverrideRegularProfile) {
   // values.
   {
     std::vector<std::pair<GURL, double>> kExpectedResults = {
-        {kUrl2, 0.0}, {kUrl1, 1.0 / 21.0},
+        {kUrl2, 0.05}, {kUrl1, 1.0 / 21.0},
     };
 
     const auto& scores = GetAllStoredScores(incognito_service);
@@ -420,14 +420,14 @@ TEST_F(MediaEngagementServiceTest, CleanupOriginsOnHistoryDeletion) {
   // Check that the scores are valid at the beginning.
   ExpectScores(origin1, 7.0 / 11.0,
                MediaEngagementScore::GetScoreMinVisits() + 2, 14, TimeNotSet());
-  EXPECT_TRUE(GetActualScore(origin1));
-  ExpectScores(origin2, 0.0, 2, 1, TimeNotSet());
-  EXPECT_FALSE(GetActualScore(origin2));
-  ExpectScores(origin3, 0.0, 2, 1, TimeNotSet());
-  EXPECT_FALSE(GetActualScore(origin3));
+  EXPECT_EQ(14.0 / 22.0, GetActualScore(origin1));
+  ExpectScores(origin2, 0.05, 2, 1, TimeNotSet());
+  EXPECT_EQ(1 / 20.0, GetActualScore(origin2));
+  ExpectScores(origin3, 0.05, 2, 1, TimeNotSet());
+  EXPECT_EQ(1 / 20.0, GetActualScore(origin3));
   ExpectScores(origin4, 0.5, MediaEngagementScore::GetScoreMinVisits(), 10,
                TimeNotSet());
-  EXPECT_TRUE(GetActualScore(origin4));
+  EXPECT_EQ(0.5, GetActualScore(origin4));
 
   {
     base::HistogramTester histogram_tester;
@@ -446,9 +446,9 @@ TEST_F(MediaEngagementServiceTest, CleanupOriginsOnHistoryDeletion) {
     // visits. origin4 should have the old score.
     ExpectScores(origin1, 0.6, MediaEngagementScore::GetScoreMinVisits(), 12,
                  TimeNotSet());
-    EXPECT_TRUE(GetActualScore(origin1));
+    EXPECT_EQ(12.0 / 20.0, GetActualScore(origin1));
     ExpectScores(origin2, 0.0, 1, 0, TimeNotSet());
-    EXPECT_FALSE(GetActualScore(origin2));
+    EXPECT_EQ(0, GetActualScore(origin2));
     ExpectScores(origin3, 0.0, 1, 0, TimeNotSet());
     ExpectScores(origin4, 0.5, MediaEngagementScore::GetScoreMinVisits(), 10,
                  TimeNotSet());
@@ -456,7 +456,7 @@ TEST_F(MediaEngagementServiceTest, CleanupOriginsOnHistoryDeletion) {
     histogram_tester.ExpectTotalCount(
         MediaEngagementService::kHistogramURLsDeletedScoreReductionName, 3);
     histogram_tester.ExpectBucketCount(
-        MediaEngagementService::kHistogramURLsDeletedScoreReductionName, 0, 2);
+        MediaEngagementService::kHistogramURLsDeletedScoreReductionName, 5, 2);
     histogram_tester.ExpectBucketCount(
         MediaEngagementService::kHistogramURLsDeletedScoreReductionName, 4, 1);
   }
@@ -478,7 +478,7 @@ TEST_F(MediaEngagementServiceTest, CleanupOriginsOnHistoryDeletion) {
     waiter.Wait();
 
     // origin1's score should have changed but the rest should remain the same.
-    ExpectScores(origin1, 0.0, MediaEngagementScore::GetScoreMinVisits() - 1,
+    ExpectScores(origin1, 0.55, MediaEngagementScore::GetScoreMinVisits() - 1,
                  11, TimeNotSet());
     ExpectScores(origin2, 0.0, 1, 0, TimeNotSet());
     ExpectScores(origin3, 0.0, 1, 0, TimeNotSet());
@@ -488,7 +488,7 @@ TEST_F(MediaEngagementServiceTest, CleanupOriginsOnHistoryDeletion) {
     histogram_tester.ExpectTotalCount(
         MediaEngagementService::kHistogramURLsDeletedScoreReductionName, 1);
     histogram_tester.ExpectBucketCount(
-        MediaEngagementService::kHistogramURLsDeletedScoreReductionName, 60, 1);
+        MediaEngagementService::kHistogramURLsDeletedScoreReductionName, 5, 1);
   }
 
   {
@@ -510,7 +510,7 @@ TEST_F(MediaEngagementServiceTest, CleanupOriginsOnHistoryDeletion) {
     // origin3's score should be removed but the rest should remain the same.
     std::map<GURL, double> scores = GetScoreMapForTesting();
     EXPECT_TRUE(scores.find(origin3) == scores.end());
-    ExpectScores(origin1, 0.0, MediaEngagementScore::GetScoreMinVisits() - 1,
+    ExpectScores(origin1, 0.55, MediaEngagementScore::GetScoreMinVisits() - 1,
                  11, TimeNotSet());
     ExpectScores(origin2, 0.0, 1, 0, TimeNotSet());
     ExpectScores(origin3, 0.0, 0, 0, TimeNotSet());
@@ -536,7 +536,7 @@ TEST_F(MediaEngagementServiceTest,
 
   ClearDataBetweenTime(today - base::TimeDelta::FromDays(2),
                        today - base::TimeDelta::FromDays(1));
-  ExpectScores(origin, 0.0, 1, 1, today);
+  ExpectScores(origin, 0.05, 1, 1, today);
 }
 
 TEST_F(MediaEngagementServiceTest,
@@ -555,8 +555,8 @@ TEST_F(MediaEngagementServiceTest,
   SetLastMediaPlaybackTime(origin2, two_days_ago);
 
   ClearDataBetweenTime(two_days_ago, yesterday);
-  ExpectScores(origin1, 0.0, 0, 0, TimeNotSet());
-  ExpectScores(origin2, 0.0, 0, 0, TimeNotSet());
+  ExpectScores(origin1, 0, 0, 0, TimeNotSet());
+  ExpectScores(origin2, 0, 0, 0, TimeNotSet());
 }
 
 TEST_F(MediaEngagementServiceTest, CleanupDataOnSiteDataCleanup_NoTimeSet) {
@@ -583,7 +583,7 @@ TEST_F(MediaEngagementServiceTest, LogScoresOnStartupToHistogram) {
 
   ExpectScores(url1, 5.0 / 6.0, 24, 20, TimeNotSet());
   ExpectScores(url2, 0.5, 24, 12, TimeNotSet());
-  ExpectScores(url3, 0.0, 1, 1, Now());
+  ExpectScores(url3, 0.05, 1, 1, Now());
 
   base::HistogramTester histogram_tester;
   std::unique_ptr<MediaEngagementService> new_service =
@@ -594,7 +594,7 @@ TEST_F(MediaEngagementServiceTest, LogScoresOnStartupToHistogram) {
   histogram_tester.ExpectTotalCount(
       MediaEngagementService::kHistogramScoreAtStartupName, 3);
   histogram_tester.ExpectBucketCount(
-      MediaEngagementService::kHistogramScoreAtStartupName, 0, 1);
+      MediaEngagementService::kHistogramScoreAtStartupName, 5, 1);
   histogram_tester.ExpectBucketCount(
       MediaEngagementService::kHistogramScoreAtStartupName, 50, 1);
   histogram_tester.ExpectBucketCount(
@@ -635,6 +635,6 @@ TEST_F(MediaEngagementServiceTest, SchemaVersion_Same) {
       base::WrapUnique<MediaEngagementService>(
           StartNewMediaEngagementService());
 
-  ExpectScores(new_service.get(), url, 0.0, 1, 2, TimeNotSet());
+  ExpectScores(new_service.get(), url, 0.1, 1, 2, TimeNotSet());
   new_service->Shutdown();
 }

chrome/browser/media/media_engagement_session_unittest.cc

@@ -548,7 +548,7 @@ TEST_F(MediaEngagementSessionTest, RecordUkmMetrics) {
                      ukm_entry, Entry::kPlaybacks_TotalName));
     EXPECT_EQ(1, *test_ukm_recorder().GetEntryMetric(ukm_entry,
                                                      Entry::kVisits_TotalName));
-    EXPECT_EQ(0, *test_ukm_recorder().GetEntryMetric(
+    EXPECT_EQ(5, *test_ukm_recorder().GetEntryMetric(
                      ukm_entry, Entry::kEngagement_ScoreName));
     EXPECT_EQ(1, *test_ukm_recorder().GetEntryMetric(
                      ukm_entry, Entry::kPlaybacks_DeltaName));
@@ -581,8 +581,8 @@ TEST_F(MediaEngagementSessionTest, RecordUkmMetrics) {
                      ukm_entry, Entry::kPlaybacks_TotalName));
     EXPECT_EQ(1, *test_ukm_recorder().GetEntryMetric(ukm_entry,
                                                      Entry::kVisits_TotalName));
-    EXPECT_EQ(0, *test_ukm_recorder().GetEntryMetric(
-                     ukm_entry, Entry::kEngagement_ScoreName));
+    EXPECT_EQ(10, *test_ukm_recorder().GetEntryMetric(
+                      ukm_entry, Entry::kEngagement_ScoreName));
     EXPECT_EQ(1, *test_ukm_recorder().GetEntryMetric(
                      ukm_entry, Entry::kPlaybacks_DeltaName));
     EXPECT_EQ(0, *test_ukm_recorder().GetEntryMetric(