chrome/browser/signin/services/android/java/src/org/chromium/chrome/browser/signin/services/FREMobileIdentityConsistencyFieldTrial.java - chromium/src - Git at Google

 // Copyright 2021 The Chromium Authors
 // 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.signin.services;

 import android.util.Pair;

 import androidx.annotation.AnyThread;
 import androidx.annotation.IntDef;
 import androidx.annotation.MainThread;
 import androidx.annotation.VisibleForTesting;

 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.chrome.browser.preferences.ChromePreferenceKeys;
 import org.chromium.chrome.browser.preferences.SharedPreferencesManager;
 import org.chromium.components.metrics.LowEntropySource;
 import org.chromium.components.variations.NormalizedMurmurHashEntropyProvider;
 import org.chromium.components.version_info.Channel;
 import org.chromium.components.version_info.VersionConstants;

 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;

 /**
  * Creates a Field Trial to control the MobileIdentityConsistencyFRE feature. This feature is used
  * to show a new First Run page that will let users sign into chrome without syncing. The trial is
  * client controlled because this experiment runs on First Run Experience when native code is not
  * initialized and variation seed in not available.
  *
  * After creating a field trial the group information is saved in {@link SharedPreferencesManager}
  * so that it's available in subsequent runs of Chrome.
  */
 public class FREMobileIdentityConsistencyFieldTrial {
     private static final Object LOCK = new Object();

     /**
      * Used as a seed while selecting the group for the trial.
      */
     private static final int STUDY_RANDOMIZATION_SALT = 0xee9a496f;

     /**
      * The group variation values should be consecutive starting from zero. WELCOME_TO_CHROME acts
      * as the control group of the experiment.
      * If a new group needs to be added then another control group must also be added.
      */
     @VisibleForTesting
     @Retention(RetentionPolicy.SOURCE)
     @IntDef({
             VariationsGroup.DEFAULT,
             VariationsGroup.WELCOME_TO_CHROME,
             VariationsGroup.WELCOME_TO_CHROME_MOST_OUT_OF_CHROME,
             VariationsGroup.WELCOME_TO_CHROME_ADDITIONAL_FEATURES,
             VariationsGroup.WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES,
             VariationsGroup.MOST_OUT_OF_CHROME,
             VariationsGroup.MAKE_CHROME_YOUR_OWN,
             VariationsGroup.MAX_VALUE,
     })
     public @interface VariationsGroup {
         /**
          * Default group of the experiment which is the group WELCOME_TO_CHROME.
          *
          * Title: 'Welcome to Chrome'
          * Subtitle: None
          */
         int DEFAULT = -1;
         /**
          * Title: 'Welcome to Chrome'
          * Subtitle: None
          */
         int WELCOME_TO_CHROME = 0;
         /**
          * Title: 'Welcome to Chrome'
          * Subtitle: 'Sign in to get the most out of Chrome'
          */
         int WELCOME_TO_CHROME_MOST_OUT_OF_CHROME = 1;
         /**
          * Title: 'Welcome to Chrome'
          * Subtitle: 'Sign in for additional features'
          */
         int WELCOME_TO_CHROME_ADDITIONAL_FEATURES = 2;
         /**
          * Title: 'Welcome to Chrome'
          * Subtitle: 'Sign in to browse easier across devices'
          */
         int WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES = 3;
         /**
          * Title: 'Sign in to get the most out of Chrome'
          * Subtitle: None
          */
         int MOST_OUT_OF_CHROME = 4;
         /**
          * Title: 'Sign in to make Chrome your own'
          * Subtitle: None
          */
         int MAKE_CHROME_YOUR_OWN = 5;
         /**
          * When adding new groups, increasing this value will automatically cause new groups
          * to receive clients. A different control group will need to be implemented however
          * when adding new groups.
          */
         int MAX_VALUE = 6;
     }

     @AnyThread
     @VariationsGroup
     private static int getFirstRunTrialGroup() {
         synchronized (LOCK) {
             return SharedPreferencesManager.getInstance().readInt(
                     ChromePreferenceKeys.FIRST_RUN_VARIATIONS_FIELD_TRIAL_GROUP,
                     VariationsGroup.DEFAULT);
         }
     }

     @CalledByNative
     @AnyThread
     private static int getFirstRunTrialVariationId(int lowEntropySource, int lowEntropySize) {
         @VariationsGroup
         int groupFromPrefs = getFirstRunTrialGroup();
         final int variationsEmptyID = 0; // This should be identical to variations::EMPTY_ID.
         if (groupFromPrefs == VariationsGroup.DEFAULT) {
             return variationsEmptyID; // Do not send variations ID if the user is the default group.
         }

         @VariationsGroup
         int groupFromLowEntropySource =
                 generateFirstRunStringVariationsGroup(lowEntropySource, lowEntropySize);
         boolean isGroupConsistent = groupFromPrefs == groupFromLowEntropySource;
         RecordHistogram.recordBooleanHistogram(
                 "Signin.AndroidIsFREStudyGroupConsistent", isGroupConsistent);

         if (!isGroupConsistent) {
             return variationsEmptyID; // Do not send variations ID if there's a mismatch.
         }
         if (VersionConstants.CHANNEL == Channel.STABLE) {
             // IDs in this method were obtained following go/finch-allocating-gws-ids.
             switch (groupFromPrefs) {
                 case VariationsGroup.WELCOME_TO_CHROME:
                     return 3362112;
                 case VariationsGroup.WELCOME_TO_CHROME_MOST_OUT_OF_CHROME:
                     return 3362113;
                 case VariationsGroup.WELCOME_TO_CHROME_ADDITIONAL_FEATURES:
                     return 3362114;
                 case VariationsGroup.WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES:
                     return 3362115;
                 case VariationsGroup.MOST_OUT_OF_CHROME:
                     return 3362116;
                 case VariationsGroup.MAKE_CHROME_YOUR_OWN:
                     return 3362117;
                 case VariationsGroup.MAX_VALUE:
                     return variationsEmptyID;
             }
         } else if (VersionConstants.CHANNEL == Channel.BETA) {
             switch (groupFromPrefs) {
                 case VariationsGroup.WELCOME_TO_CHROME:
                     return 3362120;
                 case VariationsGroup.WELCOME_TO_CHROME_MOST_OUT_OF_CHROME:
                     return 3362121;
                 case VariationsGroup.WELCOME_TO_CHROME_ADDITIONAL_FEATURES:
                     return 3362122;
                 case VariationsGroup.WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES:
                     return 3362123;
                 case VariationsGroup.MOST_OUT_OF_CHROME:
                     return 3362124;
                 case VariationsGroup.MAKE_CHROME_YOUR_OWN:
                     return 3362125;
                 case VariationsGroup.MAX_VALUE:
                     return variationsEmptyID;
             }
         }
         return variationsEmptyID; // In other channels, the experiment is not GWS-visible.
     }

     @CalledByNative
     @AnyThread
     public static String getFirstRunVariationsTrialGroupName() {
         @VariationsGroup
         final int group = getFirstRunTrialGroup();
         switch (group) {
             case VariationsGroup.WELCOME_TO_CHROME:
                 return "Control";
             case VariationsGroup.WELCOME_TO_CHROME_MOST_OUT_OF_CHROME:
                 return "WelcomeToChrome_MostOutOfChrome";
             case VariationsGroup.WELCOME_TO_CHROME_ADDITIONAL_FEATURES:
                 return "WelcomeToChrome_StrongestSecurity";
             case VariationsGroup.WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES:
                 return "WelcomeToChrome_EasierAcrossDevices";
             case VariationsGroup.MOST_OUT_OF_CHROME:
                 return "MostOutOfChrome";
             case VariationsGroup.MAKE_CHROME_YOUR_OWN:
                 return "MakeChromeYourOwn";
             default:
                 return "Default";
         }
     }

     /**
      * Returns different titles and subtitles depending upon the group variation.
      *
      * The first integer holds the string resource value for the title and the second integer
      * for the subtitle. The second integer may be 0, in which case there is no subtitle.
      */
     @MainThread
     public static Pair<Integer, Integer> getVariationTitleAndSubtitle() {
         @VariationsGroup
         final int group = getFirstRunTrialGroup();
         switch (group) {
             case VariationsGroup.WELCOME_TO_CHROME:
                 return new Pair(R.string.fre_welcome, 0);
             case VariationsGroup.WELCOME_TO_CHROME_MOST_OUT_OF_CHROME:
                 return new Pair(R.string.fre_welcome, R.string.signin_fre_subtitle_variation_1);
             case VariationsGroup.WELCOME_TO_CHROME_ADDITIONAL_FEATURES:
                 return new Pair(R.string.fre_welcome, R.string.signin_fre_subtitle_variation_2);
             case VariationsGroup.WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES:
                 return new Pair(R.string.fre_welcome, R.string.signin_fre_subtitle_variation_3);
             case VariationsGroup.MOST_OUT_OF_CHROME:
                 return new Pair(R.string.signin_fre_title_variation_1, 0);
             case VariationsGroup.MAKE_CHROME_YOUR_OWN:
                 return new Pair(R.string.signin_fre_title_variation_2, 0);
             default:
                 // By default VariationsGroup.WELCOME_TO_CHROME UI is shown in the fre.
                 return new Pair(R.string.fre_welcome, 0);
         }
     }

     @VariationsGroup
     private static int generateFirstRunStringVariationsGroup(
             int lowEntropyValue, int lowEntropySize) {
         int variationsPercentage = 0;
         switch (VersionConstants.CHANNEL) {
             case Channel.DEFAULT:
             case Channel.CANARY:
             case Channel.DEV:
                 variationsPercentage = 10;
                 break;
             case Channel.BETA:
             case Channel.STABLE:
         }
         // For A/B testing all experiment groups should have the same percentages.
         assert variationsPercentage * VariationsGroup.MAX_VALUE <= 100;

         NormalizedMurmurHashEntropyProvider entropyProvider =
                 new NormalizedMurmurHashEntropyProvider(lowEntropyValue, lowEntropySize);
         double entropyForTrial = entropyProvider.getEntropyForTrial(STUDY_RANDOMIZATION_SALT);
         double randomBucket = entropyForTrial * 100;

         if (randomBucket < variationsPercentage * VariationsGroup.MAX_VALUE) {
             return (int) (randomBucket / variationsPercentage);
         }

         return VariationsGroup.DEFAULT;
     }

     /**
      * Returns whether the title and the subtitle should be hidden until native code and policies
      * are loaded on device.
      */
     @MainThread
     public static boolean shouldHideTitleUntilPoliciesAreLoaded() {
         @VariationsGroup
         final int group = getFirstRunTrialGroup();
         return group != VariationsGroup.DEFAULT && group != VariationsGroup.WELCOME_TO_CHROME;
     }

     /**
      * Creates variations of the FRE signin welcome screen with different title/subtitle
      * combinations.
      *
      * The group information is registered as a synthetic field trial in native code inside
      * ChromeBrowserFieldTrials::RegisterSyntheticTrials().
      */
     @MainThread
     public static void createFirstRunVariationsTrial() {
         // TODO(https://crbug.com/1430512): Add a test to verify that the group assignment stays
         // consistent when the user closes and reopens Chrome during the FRE.
         synchronized (LOCK) {
             // Don't create a new group if the user was already assigned a group. Can
             // happen when the user dismisses FRE without finishing the flow and starts chrome
             // again.
             if (SharedPreferencesManager.getInstance().readInt(
                         ChromePreferenceKeys.FIRST_RUN_VARIATIONS_FIELD_TRIAL_GROUP, -2)
                     != -2) {
                 return;
             }
         }
         int group = generateFirstRunStringVariationsGroup(
                 LowEntropySource.generateLowEntropySourceForFirstRunTrial(),
                 LowEntropySource.MAX_LOW_ENTROPY_SIZE);
         synchronized (LOCK) {
             SharedPreferencesManager.getInstance().writeInt(
                     ChromePreferenceKeys.FIRST_RUN_VARIATIONS_FIELD_TRIAL_GROUP, group);
         }
     }

     @AnyThread
     public static void setFirstRunVariationsTrialGroupForTesting(@VariationsGroup int group) {
         synchronized (LOCK) {
             SharedPreferencesManager.getInstance().writeInt(
                     ChromePreferenceKeys.FIRST_RUN_VARIATIONS_FIELD_TRIAL_GROUP, group);
         }
     }
 }
	// Copyright 2021 The Chromium Authors
	// 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.signin.services;

	import android.util.Pair;

	import androidx.annotation.AnyThread;
	import androidx.annotation.IntDef;
	import androidx.annotation.MainThread;
	import androidx.annotation.VisibleForTesting;

	import org.chromium.base.annotations.CalledByNative;
	import org.chromium.base.metrics.RecordHistogram;
	import org.chromium.chrome.browser.preferences.ChromePreferenceKeys;
	import org.chromium.chrome.browser.preferences.SharedPreferencesManager;
	import org.chromium.components.metrics.LowEntropySource;
	import org.chromium.components.variations.NormalizedMurmurHashEntropyProvider;
	import org.chromium.components.version_info.Channel;
	import org.chromium.components.version_info.VersionConstants;

	import java.lang.annotation.Retention;
	import java.lang.annotation.RetentionPolicy;

	/**
	* Creates a Field Trial to control the MobileIdentityConsistencyFRE feature. This feature is used
	* to show a new First Run page that will let users sign into chrome without syncing. The trial is
	* client controlled because this experiment runs on First Run Experience when native code is not
	* initialized and variation seed in not available.
	*
	* After creating a field trial the group information is saved in {@link SharedPreferencesManager}
	* so that it's available in subsequent runs of Chrome.
	*/
	public class FREMobileIdentityConsistencyFieldTrial {
	private static final Object LOCK = new Object();

	/**
	* Used as a seed while selecting the group for the trial.
	*/
	private static final int STUDY_RANDOMIZATION_SALT = 0xee9a496f;

	/**
	* The group variation values should be consecutive starting from zero. WELCOME_TO_CHROME acts
	* as the control group of the experiment.
	* If a new group needs to be added then another control group must also be added.
	*/
	@VisibleForTesting
	@Retention(RetentionPolicy.SOURCE)
	@IntDef({
	VariationsGroup.DEFAULT,
	VariationsGroup.WELCOME_TO_CHROME,
	VariationsGroup.WELCOME_TO_CHROME_MOST_OUT_OF_CHROME,
	VariationsGroup.WELCOME_TO_CHROME_ADDITIONAL_FEATURES,
	VariationsGroup.WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES,
	VariationsGroup.MOST_OUT_OF_CHROME,
	VariationsGroup.MAKE_CHROME_YOUR_OWN,
	VariationsGroup.MAX_VALUE,
	})
	public @interface VariationsGroup {
	/**
	* Default group of the experiment which is the group WELCOME_TO_CHROME.
	*
	* Title: 'Welcome to Chrome'
	* Subtitle: None
	*/
	int DEFAULT = -1;
	/**
	* Title: 'Welcome to Chrome'
	* Subtitle: None
	*/
	int WELCOME_TO_CHROME = 0;
	/**
	* Title: 'Welcome to Chrome'
	* Subtitle: 'Sign in to get the most out of Chrome'
	*/
	int WELCOME_TO_CHROME_MOST_OUT_OF_CHROME = 1;
	/**
	* Title: 'Welcome to Chrome'
	* Subtitle: 'Sign in for additional features'
	*/
	int WELCOME_TO_CHROME_ADDITIONAL_FEATURES = 2;
	/**
	* Title: 'Welcome to Chrome'
	* Subtitle: 'Sign in to browse easier across devices'
	*/
	int WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES = 3;
	/**
	* Title: 'Sign in to get the most out of Chrome'
	* Subtitle: None
	*/
	int MOST_OUT_OF_CHROME = 4;
	/**
	* Title: 'Sign in to make Chrome your own'
	* Subtitle: None
	*/
	int MAKE_CHROME_YOUR_OWN = 5;
	/**
	* When adding new groups, increasing this value will automatically cause new groups
	* to receive clients. A different control group will need to be implemented however
	* when adding new groups.
	*/
	int MAX_VALUE = 6;
	}

	@AnyThread
	@VariationsGroup
	private static int getFirstRunTrialGroup() {
	synchronized (LOCK) {
	return SharedPreferencesManager.getInstance().readInt(
	ChromePreferenceKeys.FIRST_RUN_VARIATIONS_FIELD_TRIAL_GROUP,
	VariationsGroup.DEFAULT);
	}
	}

	@CalledByNative
	@AnyThread
	private static int getFirstRunTrialVariationId(int lowEntropySource, int lowEntropySize) {
	@VariationsGroup
	int groupFromPrefs = getFirstRunTrialGroup();
	final int variationsEmptyID = 0; // This should be identical to variations::EMPTY_ID.
	if (groupFromPrefs == VariationsGroup.DEFAULT) {
	return variationsEmptyID; // Do not send variations ID if the user is the default group.
	}

	@VariationsGroup
	int groupFromLowEntropySource =
	generateFirstRunStringVariationsGroup(lowEntropySource, lowEntropySize);
	boolean isGroupConsistent = groupFromPrefs == groupFromLowEntropySource;
	RecordHistogram.recordBooleanHistogram(
	"Signin.AndroidIsFREStudyGroupConsistent", isGroupConsistent);

	if (!isGroupConsistent) {
	return variationsEmptyID; // Do not send variations ID if there's a mismatch.
	}
	if (VersionConstants.CHANNEL == Channel.STABLE) {
	// IDs in this method were obtained following go/finch-allocating-gws-ids.
	switch (groupFromPrefs) {
	case VariationsGroup.WELCOME_TO_CHROME:
	return 3362112;
	case VariationsGroup.WELCOME_TO_CHROME_MOST_OUT_OF_CHROME:
	return 3362113;
	case VariationsGroup.WELCOME_TO_CHROME_ADDITIONAL_FEATURES:
	return 3362114;
	case VariationsGroup.WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES:
	return 3362115;
	case VariationsGroup.MOST_OUT_OF_CHROME:
	return 3362116;
	case VariationsGroup.MAKE_CHROME_YOUR_OWN:
	return 3362117;
	case VariationsGroup.MAX_VALUE:
	return variationsEmptyID;
	}
	} else if (VersionConstants.CHANNEL == Channel.BETA) {
	switch (groupFromPrefs) {
	case VariationsGroup.WELCOME_TO_CHROME:
	return 3362120;
	case VariationsGroup.WELCOME_TO_CHROME_MOST_OUT_OF_CHROME:
	return 3362121;
	case VariationsGroup.WELCOME_TO_CHROME_ADDITIONAL_FEATURES:
	return 3362122;
	case VariationsGroup.WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES:
	return 3362123;
	case VariationsGroup.MOST_OUT_OF_CHROME:
	return 3362124;
	case VariationsGroup.MAKE_CHROME_YOUR_OWN:
	return 3362125;
	case VariationsGroup.MAX_VALUE:
	return variationsEmptyID;
	}
	}
	return variationsEmptyID; // In other channels, the experiment is not GWS-visible.
	}

	@CalledByNative
	@AnyThread
	public static String getFirstRunVariationsTrialGroupName() {
	@VariationsGroup
	final int group = getFirstRunTrialGroup();
	switch (group) {
	case VariationsGroup.WELCOME_TO_CHROME:
	return "Control";
	case VariationsGroup.WELCOME_TO_CHROME_MOST_OUT_OF_CHROME:
	return "WelcomeToChrome_MostOutOfChrome";
	case VariationsGroup.WELCOME_TO_CHROME_ADDITIONAL_FEATURES:
	return "WelcomeToChrome_StrongestSecurity";
	case VariationsGroup.WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES:
	return "WelcomeToChrome_EasierAcrossDevices";
	case VariationsGroup.MOST_OUT_OF_CHROME:
	return "MostOutOfChrome";
	case VariationsGroup.MAKE_CHROME_YOUR_OWN:
	return "MakeChromeYourOwn";
	default:
	return "Default";
	}
	}

	/**
	* Returns different titles and subtitles depending upon the group variation.
	*
	* The first integer holds the string resource value for the title and the second integer
	* for the subtitle. The second integer may be 0, in which case there is no subtitle.
	*/
	@MainThread
	public static Pair<Integer, Integer> getVariationTitleAndSubtitle() {
	@VariationsGroup
	final int group = getFirstRunTrialGroup();
	switch (group) {
	case VariationsGroup.WELCOME_TO_CHROME:
	return new Pair(R.string.fre_welcome, 0);
	case VariationsGroup.WELCOME_TO_CHROME_MOST_OUT_OF_CHROME:
	return new Pair(R.string.fre_welcome, R.string.signin_fre_subtitle_variation_1);
	case VariationsGroup.WELCOME_TO_CHROME_ADDITIONAL_FEATURES:
	return new Pair(R.string.fre_welcome, R.string.signin_fre_subtitle_variation_2);
	case VariationsGroup.WELCOME_TO_CHROME_EASIER_ACROSS_DEVICES:
	return new Pair(R.string.fre_welcome, R.string.signin_fre_subtitle_variation_3);
	case VariationsGroup.MOST_OUT_OF_CHROME:
	return new Pair(R.string.signin_fre_title_variation_1, 0);
	case VariationsGroup.MAKE_CHROME_YOUR_OWN:
	return new Pair(R.string.signin_fre_title_variation_2, 0);
	default:
	// By default VariationsGroup.WELCOME_TO_CHROME UI is shown in the fre.
	return new Pair(R.string.fre_welcome, 0);
	}
	}

	@VariationsGroup
	private static int generateFirstRunStringVariationsGroup(
	int lowEntropyValue, int lowEntropySize) {
	int variationsPercentage = 0;
	switch (VersionConstants.CHANNEL) {
	case Channel.DEFAULT:
	case Channel.CANARY:
	case Channel.DEV:
	variationsPercentage = 10;
	break;
	case Channel.BETA:
	case Channel.STABLE:
	}
	// For A/B testing all experiment groups should have the same percentages.
	assert variationsPercentage * VariationsGroup.MAX_VALUE <= 100;

	NormalizedMurmurHashEntropyProvider entropyProvider =
	new NormalizedMurmurHashEntropyProvider(lowEntropyValue, lowEntropySize);
	double entropyForTrial = entropyProvider.getEntropyForTrial(STUDY_RANDOMIZATION_SALT);
	double randomBucket = entropyForTrial * 100;

	if (randomBucket < variationsPercentage * VariationsGroup.MAX_VALUE) {
	return (int) (randomBucket / variationsPercentage);
	}

	return VariationsGroup.DEFAULT;
	}

	/**
	* Returns whether the title and the subtitle should be hidden until native code and policies
	* are loaded on device.
	*/
	@MainThread
	public static boolean shouldHideTitleUntilPoliciesAreLoaded() {
	@VariationsGroup
	final int group = getFirstRunTrialGroup();
	return group != VariationsGroup.DEFAULT && group != VariationsGroup.WELCOME_TO_CHROME;
	}

	/**
	* Creates variations of the FRE signin welcome screen with different title/subtitle
	* combinations.
	*
	* The group information is registered as a synthetic field trial in native code inside
	* ChromeBrowserFieldTrials::RegisterSyntheticTrials().
	*/
	@MainThread
	public static void createFirstRunVariationsTrial() {
	// TODO(https://crbug.com/1430512): Add a test to verify that the group assignment stays
	// consistent when the user closes and reopens Chrome during the FRE.
	synchronized (LOCK) {
	// Don't create a new group if the user was already assigned a group. Can
	// happen when the user dismisses FRE without finishing the flow and starts chrome
	// again.
	if (SharedPreferencesManager.getInstance().readInt(
	ChromePreferenceKeys.FIRST_RUN_VARIATIONS_FIELD_TRIAL_GROUP, -2)
	!= -2) {
	return;
	}
	}
	int group = generateFirstRunStringVariationsGroup(
	LowEntropySource.generateLowEntropySourceForFirstRunTrial(),
	LowEntropySource.MAX_LOW_ENTROPY_SIZE);
	synchronized (LOCK) {
	SharedPreferencesManager.getInstance().writeInt(
	ChromePreferenceKeys.FIRST_RUN_VARIATIONS_FIELD_TRIAL_GROUP, group);
	}
	}

	@AnyThread
	public static void setFirstRunVariationsTrialGroupForTesting(@VariationsGroup int group) {
	synchronized (LOCK) {
	SharedPreferencesManager.getInstance().writeInt(
	ChromePreferenceKeys.FIRST_RUN_VARIATIONS_FIELD_TRIAL_GROUP, group);
	}
	}
	}