[HomepagePromo] Add two finch flags for homepage promo experiment

Add two finch flags to collect synthetic trial data for enable/tracking-
only group that users has "seen" the homepage promo.

Bug: 1068831, 1084292
Change-Id: Ibf798c0f814c215fd958af2e9463828358b23be2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2208271
Commit-Queue: Wenyu Fu <wenyufu@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#773382}

chrome/android/chrome_junit_test_java_sources.gni

@@ -138,6 +138,7 @@ chrome_junit_test_java_sources = [
   "junit/src/org/chromium/chrome/browser/ntp/TitleUtilTest.java",
   "junit/src/org/chromium/chrome/browser/ntp/cards/InnerNodeTest.java",
   "junit/src/org/chromium/chrome/browser/ntp/cards/promo/HomepagePromoUnitTest.java",
+  "junit/src/org/chromium/chrome/browser/ntp/cards/promo/HomepagePromoVariationManagerTest.java",
   "junit/src/org/chromium/chrome/browser/offlinepages/BackgroundSchedulerTest.java",
   "junit/src/org/chromium/chrome/browser/offlinepages/CctOfflinePageModelObserverTest.java",
   "junit/src/org/chromium/chrome/browser/offlinepages/ClientIdTest.java",

chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java

@@ -106,6 +106,7 @@ import org.chromium.chrome.browser.navigation_predictor.NavigationPredictorBridg
 import org.chromium.chrome.browser.night_mode.WebContentsDarkModeController;
 import org.chromium.chrome.browser.ntp.NewTabPage;
 import org.chromium.chrome.browser.ntp.NewTabPageUma;
+import org.chromium.chrome.browser.ntp.cards.promo.HomepagePromoVariationManager;
 import org.chromium.chrome.browser.omaha.OmahaBase;
 import org.chromium.chrome.browser.omnibox.LocationBar;
 import org.chromium.chrome.browser.paint_preview.PaintPreviewTabHelper;
@@ -1677,6 +1678,8 @@ public class ChromeTabbedActivity extends ChromeActivity<ChromeActivityComponent
             LauncherShortcutActivity.updateIncognitoShortcut(ChromeTabbedActivity.this);
 
             ChromeSurveyController.initialize(mTabModelSelectorImpl);
+
+            HomepagePromoVariationManager.getInstance().tagSyntheticHomepagePromoSeenGroup();
         });
     }
 

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/promo/HomepagePromoVariationManager.java

@@ -7,8 +7,13 @@ package org.chromium.chrome.browser.ntp.cards.promo;
 import androidx.annotation.StringDef;
 import androidx.annotation.VisibleForTesting;
 
+import org.chromium.chrome.browser.feature_engagement.TrackerFactory;
 import org.chromium.chrome.browser.flags.ChromeFeatureList;
+import org.chromium.chrome.browser.metrics.UmaSessionStats;
+import org.chromium.chrome.browser.profiles.Profile;
 import org.chromium.components.browser_ui.widget.promo.PromoCardCoordinator.LayoutStyle;
+import org.chromium.components.feature_engagement.FeatureConstants;
+import org.chromium.components.feature_engagement.Tracker;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -26,8 +31,23 @@ public class HomepagePromoVariationManager {
         String SLIM = "Slim";
     }
 
+    // A helper class for Synthetic Field trial helper. Adding to makes test easier.
+    interface SyntheticTrialHelper {
+        boolean hasEverTriggered();
+
+        void registerSyntheticFieldTrial(String groupName);
+
+        boolean isClientInIPHTrackingOnlyGroup();
+
+        boolean isClientInEnabledStudyGroup();
+
+        boolean isClientInTrackingStudyGroup();
+    }
+
     private static HomepagePromoVariationManager sInstance;
 
+    private SyntheticTrialHelper mStudyHelper;
+
     /**
      * @return Singleton instance for {@link HomepagePromoVariationManager}.
      */
@@ -38,6 +58,43 @@ public class HomepagePromoVariationManager {
         return sInstance;
     }
 
+    private HomepagePromoVariationManager() {
+        mStudyHelper = new SyntheticTrialHelper() {
+            @Override
+            public boolean hasEverTriggered() {
+                Tracker tracker =
+                        TrackerFactory.getTrackerForProfile(Profile.getLastUsedRegularProfile());
+
+                return tracker.hasEverTriggered(
+                        FeatureConstants.HOMEPAGE_PROMO_CARD_FEATURE, false);
+            }
+
+            @Override
+            public void registerSyntheticFieldTrial(String groupName) {
+                UmaSessionStats.registerSyntheticFieldTrial(
+                        FeatureConstants.HOMEPAGE_PROMO_CARD_FEATURE, groupName);
+            }
+
+            @Override
+            public boolean isClientInIPHTrackingOnlyGroup() {
+                return ChromeFeatureList.getFieldTrialParamByFeatureAsBoolean(
+                        FeatureConstants.HOMEPAGE_PROMO_CARD_FEATURE, "tracking-only", false);
+            }
+
+            @Override
+            public boolean isClientInEnabledStudyGroup() {
+                return ChromeFeatureList.isEnabled(
+                        ChromeFeatureList.HOMEPAGE_PROMO_SYNTHETIC_PROMO_SEEN_ENABLED);
+            }
+
+            @Override
+            public boolean isClientInTrackingStudyGroup() {
+                return ChromeFeatureList.isEnabled(
+                        ChromeFeatureList.HOMEPAGE_PROMO_SYNTHETIC_PROMO_SEEN_TRACKING);
+            }
+        };
+    }
+
     @VisibleForTesting
     public static void setInstanceForTesting(HomepagePromoVariationManager mock) {
         sInstance = mock;
@@ -64,4 +121,26 @@ public class HomepagePromoVariationManager {
 
         return LayoutStyle.COMPACT;
     }
+
+    /**
+     * If the user has ever seen the homepage promo, add a synthetic tag to the user.
+     */
+    public void tagSyntheticHomepagePromoSeenGroup() {
+        if (mStudyHelper.hasEverTriggered()) {
+            boolean isTrackingOnly = mStudyHelper.isClientInIPHTrackingOnlyGroup();
+
+            if (!isTrackingOnly && !mStudyHelper.isClientInEnabledStudyGroup()) {
+                mStudyHelper.registerSyntheticFieldTrial(
+                        ChromeFeatureList.HOMEPAGE_PROMO_SYNTHETIC_PROMO_SEEN_ENABLED);
+            } else if (isTrackingOnly && !mStudyHelper.isClientInTrackingStudyGroup()) {
+                mStudyHelper.registerSyntheticFieldTrial(
+                        ChromeFeatureList.HOMEPAGE_PROMO_SYNTHETIC_PROMO_SEEN_TRACKING);
+            }
+        }
+    }
+
+    @VisibleForTesting
+    void setStudyHelperForTests(SyntheticTrialHelper helper) {
+        mStudyHelper = helper;
+    }
 }

chrome/android/javatests/src/org/chromium/chrome/browser/ntp/cards/promo/HomepagePromoTest.java

@@ -126,6 +126,7 @@ public class HomepagePromoTest {
         Mockito.when(mTracker.shouldTriggerHelpUI(FeatureConstants.HOMEPAGE_PROMO_CARD_FEATURE))
                 .thenReturn(true);
         TrackerFactory.setTrackerForTests(mTracker);
+        HomepagePromoVariationManager.setInstanceForTesting(mMockVariationManager);
 
         // By default, use default homepage just like a first time user.
         mHomepageTestRule.useDefaultHomepageForTest();
@@ -361,6 +362,9 @@ public class HomepagePromoTest {
     @Test
     @SmallTest
     public void testExperimentTrackerSignals() {
+        // Tagging for synthetic trial should happen once.
+        Mockito.verify(mMockVariationManager, times(1)).tagSyntheticHomepagePromoSeenGroup();
+
         mHomepageTestRule.useChromeNTPForTest();
         ToolbarManager toolbarManager = mActivityTestRule.getActivity().getToolbarManager();
 
@@ -395,6 +399,5 @@ public class HomepagePromoTest {
 
     private void setVariationForTests(@LayoutStyle int variation) {
         Mockito.when(mMockVariationManager.getLayoutVariation()).thenReturn(variation);
-        HomepagePromoVariationManager.setInstanceForTesting(mMockVariationManager);
     }
 }

chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/promo/HomepagePromoVariationManagerTest.java

+// Copyright 2020 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.
+
+package org.chromium.chrome.browser.ntp.cards.promo;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+
+import androidx.test.filters.SmallTest;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+
+import org.chromium.base.test.BaseRobolectricTestRunner;
+import org.chromium.chrome.browser.flags.ChromeFeatureList;
+
+/**
+ * Unit test for {@link HomepagePromoVariationManager}.
+ */
+@RunWith(BaseRobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class HomepagePromoVariationManagerTest {
+    private static final String STUDY_ENABLED_GROUP =
+            ChromeFeatureList.HOMEPAGE_PROMO_SYNTHETIC_PROMO_SEEN_ENABLED;
+    private static final String STUDY_TRACKING_GROUP =
+            ChromeFeatureList.HOMEPAGE_PROMO_SYNTHETIC_PROMO_SEEN_TRACKING;
+
+    @Mock
+    public HomepagePromoVariationManager.SyntheticTrialHelper mStudyHelper;
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.initMocks(this);
+        HomepagePromoVariationManager.getInstance().setStudyHelperForTests(mStudyHelper);
+    }
+
+    @After
+    public void tearDown() {
+        Mockito.reset(mStudyHelper);
+    }
+
+    @Test
+    @SmallTest
+    public void testStudyEnabled_EnabledGroup() {
+        setStudyHelper(true, true, false);
+
+        HomepagePromoVariationManager.getInstance().tagSyntheticHomepagePromoSeenGroup();
+
+        Mockito.verify(mStudyHelper, times(1)).isClientInIPHTrackingOnlyGroup();
+        Mockito.verify(mStudyHelper, times(1)).isClientInEnabledStudyGroup();
+        Mockito.verify(mStudyHelper, never()).isClientInTrackingStudyGroup();
+        Mockito.verify(mStudyHelper, never()).registerSyntheticFieldTrial(anyString());
+    }
+
+    @Test
+    @SmallTest
+    public void testStudyEnabled_TrackingGroup() {
+        setStudyHelper(true, true, true);
+
+        HomepagePromoVariationManager.getInstance().tagSyntheticHomepagePromoSeenGroup();
+
+        Mockito.verify(mStudyHelper, times(1)).isClientInIPHTrackingOnlyGroup();
+        Mockito.verify(mStudyHelper, never()).isClientInEnabledStudyGroup();
+        Mockito.verify(mStudyHelper, times(1)).isClientInTrackingStudyGroup();
+        Mockito.verify(mStudyHelper, never()).registerSyntheticFieldTrial(anyString());
+    }
+
+    /**
+     * If study disabled and client in enabled group, STUDY_ENABLED_GROUP should be tagged in
+     * SyntheticFieldTrial.
+     */
+    @Test
+    @SmallTest
+    public void testStudyDisabled_EnabledGroup() {
+        setStudyHelper(true, false, false);
+
+        HomepagePromoVariationManager.getInstance().tagSyntheticHomepagePromoSeenGroup();
+
+        Mockito.verify(mStudyHelper, times(1)).isClientInIPHTrackingOnlyGroup();
+        Mockito.verify(mStudyHelper, times(1)).isClientInEnabledStudyGroup();
+        Mockito.verify(mStudyHelper, never()).isClientInTrackingStudyGroup();
+
+        Mockito.verify(mStudyHelper, times(1)).registerSyntheticFieldTrial(STUDY_ENABLED_GROUP);
+        Mockito.verify(mStudyHelper, never()).registerSyntheticFieldTrial(STUDY_TRACKING_GROUP);
+    }
+
+    /**
+     * If study disabled and client in tracking-only, STUDY_TRACKING_GROUP should be tagged in
+     * SyntheticFieldTrial.
+     */
+    @Test
+    @SmallTest
+    public void testStudyDisabled_TrackingGroup() {
+        setStudyHelper(true, false, true);
+
+        HomepagePromoVariationManager.getInstance().tagSyntheticHomepagePromoSeenGroup();
+
+        Mockito.verify(mStudyHelper, times(1)).isClientInIPHTrackingOnlyGroup();
+        Mockito.verify(mStudyHelper, never()).isClientInEnabledStudyGroup();
+        Mockito.verify(mStudyHelper, times(1)).isClientInTrackingStudyGroup();
+
+        Mockito.verify(mStudyHelper, never()).registerSyntheticFieldTrial(STUDY_ENABLED_GROUP);
+        Mockito.verify(mStudyHelper, times(1)).registerSyntheticFieldTrial(STUDY_TRACKING_GROUP);
+    }
+
+    /**
+     * If promo has never triggered, none of the study flag should be triggered, and
+     * registerSyntheticFieldTrial should not happened.
+     */
+    @Test
+    @SmallTest
+    public void testNotEverTriggered() {
+        setStudyHelper(false, true, true);
+
+        HomepagePromoVariationManager.getInstance().tagSyntheticHomepagePromoSeenGroup();
+
+        Mockito.verify(mStudyHelper, never()).isClientInIPHTrackingOnlyGroup();
+        Mockito.verify(mStudyHelper, never()).isClientInEnabledStudyGroup();
+        Mockito.verify(mStudyHelper, never()).isClientInTrackingStudyGroup();
+        Mockito.verify(mStudyHelper, never()).registerSyntheticFieldTrial(any());
+    }
+
+    private void setStudyHelper(
+            boolean hasEverTriggered, boolean isStudyEnabled, boolean isInTrackingGroup) {
+        Mockito.doReturn(hasEverTriggered).when(mStudyHelper).hasEverTriggered();
+
+        Mockito.doReturn(isStudyEnabled).when(mStudyHelper).isClientInEnabledStudyGroup();
+        Mockito.doReturn(isStudyEnabled).when(mStudyHelper).isClientInTrackingStudyGroup();
+
+        Mockito.doReturn(isInTrackingGroup).when(mStudyHelper).isClientInIPHTrackingOnlyGroup();
+    }
+}

chrome/browser/flags/android/chrome_feature_list.cc

@@ -92,6 +92,7 @@ const base::Feature* kFeaturesExposedToJava[] = {
     &feature_engagement::kIPHChromeDuetHomeButtonFeature,
     &feature_engagement::kIPHChromeDuetSearchFeature,
     &feature_engagement::kIPHChromeDuetTabSwitcherFeature,
+    &feature_engagement::kIPHHomepagePromoCardFeature,
     &feed::kInterestFeedContentSuggestions,
     &feed::kInterestFeedFeedback,
     &feed::kInterestFeedV2,
@@ -155,6 +156,8 @@ const base::Feature* kFeaturesExposedToJava[] = {
     &kHandleMediaIntents,
     &kHomepageLocation,
     &kHomepagePromoCard,
+    &kHomepagePromoSyntheticPromoSeenEnabled,
+    &kHomepagePromoSyntheticPromoSeenTracking,
     &kHomepageSettingsUIConversion,
     &kHorizontalTabSwitcherAndroid,
     &kImmersiveUiMode,
@@ -450,6 +453,14 @@ const base::Feature kHomepageLocation{"HomepageLocationPolicy",
 const base::Feature kHomepagePromoCard{"HomepagePromoCard",
                                        base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Homepage Promo experiment group for synthetic field trial.
+const base::Feature kHomepagePromoSyntheticPromoSeenEnabled{
+    "HomepagePromoSyntheticPromoSeenEnabled",
+    base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kHomepagePromoSyntheticPromoSeenTracking{
+    "HomepagePromoSyntheticPromoSeenTracking",
+    base::FEATURE_DISABLED_BY_DEFAULT};
+
 const base::Feature kHomepageSettingsUIConversion{
     "HomepageSettingsUIConversion", base::FEATURE_ENABLED_BY_DEFAULT};
 

chrome/browser/flags/android/chrome_feature_list.h

@@ -74,6 +74,8 @@ extern const base::Feature kFocusOmniboxInIncognitoTabIntents;
 extern const base::Feature kHandleMediaIntents;
 extern const base::Feature kHomepageLocation;
 extern const base::Feature kHomepagePromoCard;
+extern const base::Feature kHomepagePromoSyntheticPromoSeenEnabled;
+extern const base::Feature kHomepagePromoSyntheticPromoSeenTracking;
 extern const base::Feature kHomepageSettingsUIConversion;
 extern const base::Feature kHorizontalTabSwitcherAndroid;
 extern const base::Feature kImmersiveUiMode;

chrome/browser/flags/android/java/src/org/chromium/chrome/browser/flags/ChromeFeatureList.java

@@ -289,6 +289,10 @@ public abstract class ChromeFeatureList {
     public static final String HANDLE_MEDIA_INTENTS = "HandleMediaIntents";
     public static final String HOMEPAGE_LOCATION_POLICY = "HomepageLocationPolicy";
     public static final String HOMEPAGE_PROMO_CARD = "HomepagePromoCard";
+    public static final String HOMEPAGE_PROMO_SYNTHETIC_PROMO_SEEN_ENABLED =
+            "HomepagePromoSyntheticPromoSeenEnabled";
+    public static final String HOMEPAGE_PROMO_SYNTHETIC_PROMO_SEEN_TRACKING =
+            "HomepagePromoSyntheticPromoSeenTracking";
     public static final String HOMEPAGE_SETTINGS_UI_CONVERSION = "HomepageSettingsUIConversion";
     public static final String HORIZONTAL_TAB_SWITCHER_ANDROID = "HorizontalTabSwitcherAndroid";
     public static final String IMMERSIVE_UI_MODE = "ImmersiveUiMode";