[Herb] Set up field trial for UI prototypes

* Add a field trial for bucketing users into different prototypes.
  The trial stores the herb flavor in a variations param.

* Consolidate Herb string checking into FeatureUtilities, which
  checks whether VariationsAssociatedParams are active and
  whether they're overridden by about:flags.

* Adds a "disabled" group to about:flags to explicitly disable the
  experiment, users on about:flags now default to whatever they're
  bucketed into.

* Stop toasting to the user that they need the restart Chrome for
  cached experiment flags to take effect.  Users won't understand
  why this is relevant.

BUG=582539

Review URL: https://codereview.chromium.org/1716313002

Cr-Commit-Position: refs/heads/master@{#377454}

13 files changed, 155 insertions, 83 deletions

diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
index 739bf2c..b06f9e9 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
@@ -65,7 +65,6 @@ import org.chromium.chrome.browser.partnercustomizations.PartnerBrowserCustomiza
 import org.chromium.chrome.browser.physicalweb.PhysicalWebBleClient;
 import org.chromium.chrome.browser.policy.PolicyAuditor;
 import org.chromium.chrome.browser.preferences.AccessibilityPreferences;
-import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
 import org.chromium.chrome.browser.preferences.LocationSettings;
 import org.chromium.chrome.browser.preferences.PrefServiceBridge;
 import org.chromium.chrome.browser.preferences.Preferences;
@@ -104,7 +103,6 @@ import org.chromium.sync.signin.SystemAccountManagerDelegate;
 import org.chromium.ui.UiUtils;
 import org.chromium.ui.base.ActivityWindowAndroid;
 import org.chromium.ui.base.ResourceBundle;
-import org.chromium.ui.widget.Toast;
 
 import java.lang.ref.WeakReference;
 import java.util.Locale;
@@ -866,13 +864,7 @@ public class ChromeApplication extends ContentApplication {
      */
     private void cacheNativeFlags() {
         if (sIsFinishedCachingNativeFlags) return;
-
-        boolean isToastNeeded = ChromePreferenceManager.cacheHerbFlavor();
-        if (isToastNeeded) {
-            Toast.makeText(this,
-                    R.string.cache_native_flags_requires_restart, Toast.LENGTH_SHORT).show();
-        }
-
+        FeatureUtilities.cacheHerbFlavor();
         sIsFinishedCachingNativeFlags = true;
     }
 }
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeSwitches.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeSwitches.java
index 06157fe..6116242 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeSwitches.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeSwitches.java
@@ -227,11 +227,20 @@ public abstract class ChromeSwitches {
      * Determines which of the Herb prototypes is being tested.
      * See about:flags for descriptions.
      */
-    public static final String HERB_FLAVOR = "tab-management-experiment-type";
-    public static final String HERB_FLAVOR_ANISE = "anise";
-    public static final String HERB_FLAVOR_BASIL = "basil";
-    public static final String HERB_FLAVOR_CHIVE = "chive";
-    public static final String HERB_FLAVOR_DILL = "dill";
+    public static final String HERB_FLAVOR_DISABLED_SWITCH =
+            "tab-management-experiment-type-disabled";
+    public static final String HERB_FLAVOR_ANISE_SWITCH = "tab-management-experiment-type-anise";
+    public static final String HERB_FLAVOR_BASIL_SWITCH = "tab-management-experiment-type-basil";
+    public static final String HERB_FLAVOR_CHIVE_SWITCH = "tab-management-experiment-type-chive";
+    public static final String HERB_FLAVOR_DILL_SWITCH = "tab-management-experiment-type-dill";
+
+    public static final String HERB_FLAVOR_DEFAULT = "Default";
+    public static final String HERB_FLAVOR_CONTROL = "Control";
+    public static final String HERB_FLAVOR_DISABLED = "Disabled";
+    public static final String HERB_FLAVOR_ANISE = "Anise";
+    public static final String HERB_FLAVOR_BASIL = "Basil";
+    public static final String HERB_FLAVOR_CHIVE = "Chive";
+    public static final String HERB_FLAVOR_DILL = "Dill";
 
     /**
      * Enable tab switcher in document mode (merged tabs and apps option).
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
index f92ddbe..174fe57 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
@@ -765,7 +765,7 @@ public class ChromeTabbedActivity extends ChromeActivity implements OverviewMode
             boolean isAllowedToReturnToExternalApp = IntentUtils.safeGetBooleanExtra(intent,
                     ChromeLauncherActivity.EXTRA_IS_ALLOWED_TO_RETURN_TO_PARENT, true);
 
-            String herbFlavor = ChromePreferenceManager.getHerbFlavor();
+            String herbFlavor = FeatureUtilities.getHerbFlavor();
             if (isAllowedToReturnToExternalApp
                     && ChromeLauncherActivity.canBeHijackedByHerb(intent)
                     && TextUtils.equals(ChromeSwitches.HERB_FLAVOR_DILL, herbFlavor)) {
@@ -1110,7 +1110,7 @@ public class ChromeTabbedActivity extends ChromeActivity implements OverviewMode
         if (alwaysAllowTabClosure) {
             isAllowedToCloseTab = true;
         } else {
-            String herbFlavor = ChromePreferenceManager.getHerbFlavor();
+            String herbFlavor = FeatureUtilities.getHerbFlavor();
             if (TextUtils.equals(ChromeSwitches.HERB_FLAVOR_BASIL, herbFlavor)
                     || TextUtils.equals(ChromeSwitches.HERB_FLAVOR_CHIVE, herbFlavor)) {
                 isAllowedToCloseTab = !currentTab.isAllowedToReturnToExternalApp();
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java
index 79c6db4..d0ad74c 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java
@@ -26,8 +26,9 @@ import org.chromium.base.Log;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeActivity;
+import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.IntentHandler;
-import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
+import org.chromium.chrome.browser.util.FeatureUtilities;
 import org.chromium.chrome.browser.util.IntentUtils;
 import org.chromium.chrome.browser.widget.TintedDrawable;
 
@@ -422,7 +423,11 @@ public class CustomTabIntentDataProvider {
      * @param context Context for the package.
      */
     private void parseHerbExtras(Intent intent, Context context) {
-        if (TextUtils.isEmpty(ChromePreferenceManager.getHerbFlavor())) return;
+        String herbFlavor = FeatureUtilities.getHerbFlavor();
+        if (TextUtils.isEmpty(herbFlavor)
+                || TextUtils.equals(ChromeSwitches.HERB_FLAVOR_DISABLED, herbFlavor)) {
+            return;
+        }
         if (!IntentHandler.isIntentChromeOrFirstParty(intent, context)) return;
 
         mFinishAfterOpeningInBrowser = IntentUtils.safeGetBooleanExtra(
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
index aa47784..70d9313 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
@@ -322,8 +322,9 @@ public class ChromeLauncherActivity extends Activity
         if (!canBeHijackedByHerb(getIntent())) return false;
 
         // Different Herb flavors handle incoming intents differently.
-        String flavor = ChromePreferenceManager.getHerbFlavor();
-        if (TextUtils.isEmpty(flavor)) {
+        String flavor = FeatureUtilities.getHerbFlavor();
+        if (TextUtils.isEmpty(flavor)
+                || TextUtils.equals(ChromeSwitches.HERB_FLAVOR_DISABLED, flavor)) {
             return false;
         } else if (TextUtils.equals(flavor, ChromeSwitches.HERB_FLAVOR_ANISE)
                 || TextUtils.equals(flavor, ChromeSwitches.HERB_FLAVOR_BASIL)
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceManager.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceManager.java
index 5424939..b7450d8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceManager.java
@@ -6,19 +6,13 @@ package org.chromium.chrome.browser.preferences;
 
 import android.content.Context;
 import android.content.SharedPreferences;
-import android.os.StrictMode;
 import android.preference.PreferenceManager;
-import android.text.TextUtils;
 
-import org.chromium.base.ApplicationStatus;
-import org.chromium.base.CommandLine;
-import org.chromium.base.Log;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.chrome.browser.ChromeSwitches;
-import org.chromium.chrome.browser.ChromeVersionInfo;
 import org.chromium.chrome.browser.crash.MinidumpUploadService.ProcessType;
 import org.chromium.chrome.browser.signin.SigninPromoUma;
-import org.chromium.ui.base.DeviceFormFactor;
+import org.chromium.chrome.browser.util.FeatureUtilities;
 
 import java.util.Locale;
 
@@ -59,8 +53,6 @@ public class ChromePreferenceManager {
     private static final long MILLISECONDS_IN_DAY = 1000 * 60 * 60 * 24;
 
     private static ChromePreferenceManager sPrefs;
-    private static String sCachedHerbFlavor;
-    private static boolean sIsHerbFlavorCached;
 
     private final SharedPreferences mSharedPreferences;
     private final Context mContext;
@@ -333,51 +325,18 @@ public class ChromePreferenceManager {
     }
 
     /**
-     * @return Which flavor of Herb is active, or null if a prototype isn't being tested.
+     * @return Which UI prototype the user is testing. This is cached from native via
+     *         {@link FeatureUtilities#cacheHerbFlavor}.
      */
-    public static String getHerbFlavor() {
-        if (!sIsHerbFlavorCached) {
-            Context context = ApplicationStatus.getApplicationContext();
-            if (ChromeVersionInfo.isStableBuild() || ChromeVersionInfo.isBetaBuild()) return null;
-            if (DeviceFormFactor.isTablet(context)) return null;
-
-            // Allowing disk access for preferences while prototyping.
-            sCachedHerbFlavor = null;
-            StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
-            try {
-                sCachedHerbFlavor =
-                        ChromePreferenceManager.getInstance(context).getHerbFlavorInternal();
-            } finally {
-                StrictMode.setThreadPolicy(oldPolicy);
-            }
-
-            sIsHerbFlavorCached = true;
-            Log.d(TAG, "Retrieved Herb flavor: " + sCachedHerbFlavor);
-        }
-
-        return sCachedHerbFlavor;
-    }
-
-    private String getHerbFlavorInternal() {
-        return mSharedPreferences.getString(HERB_FLAVOR_KEY, null);
+    public String getCachedHerbFlavor() {
+        return mSharedPreferences.getString(HERB_FLAVOR_KEY, ChromeSwitches.HERB_FLAVOR_DISABLED);
     }
 
     /**
-     * Caches which flavor of Herb the user prefers from native.
+     * Caches which UI prototype the user is testing.
      */
-    public static boolean cacheHerbFlavor() {
-        String oldFlavor = getHerbFlavor();
-        String newFlavor =
-                CommandLine.getInstance().getSwitchValue(ChromeSwitches.HERB_FLAVOR, null);
-        sCachedHerbFlavor = newFlavor;
-        Log.d(TAG, "Caching Herb flavor: " + sCachedHerbFlavor);
-
-        if (!TextUtils.equals(oldFlavor, newFlavor)) {
-            Context context = ApplicationStatus.getApplicationContext();
-            ChromePreferenceManager.getInstance(context).writeString(HERB_FLAVOR_KEY, newFlavor);
-            return true;
-        }
-        return false;
+    public void setCachedHerbFlavor(String flavor) {
+        writeString(HERB_FLAVOR_KEY, flavor);
     }
 
     /**
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarPhone.java b/chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarPhone.java
index 5231d42..61fa4f62 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarPhone.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarPhone.java
@@ -54,7 +54,6 @@ import org.chromium.chrome.browser.omnibox.LocationBar;
 import org.chromium.chrome.browser.omnibox.LocationBarPhone;
 import org.chromium.chrome.browser.omnibox.UrlContainer;
 import org.chromium.chrome.browser.partnercustomizations.HomepageManager;
-import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.util.ColorUtils;
 import org.chromium.chrome.browser.util.FeatureUtilities;
@@ -2150,7 +2149,7 @@ public class ToolbarPhone extends ToolbarLayout
     }
 
     private boolean isReturnButtonVisible() {
-        String herbFlavor = ChromePreferenceManager.getHerbFlavor();
+        String herbFlavor = FeatureUtilities.getHerbFlavor();
         if (!TextUtils.equals(ChromeSwitches.HERB_FLAVOR_BASIL, herbFlavor)
                 && !TextUtils.equals(ChromeSwitches.HERB_FLAVOR_CHIVE, herbFlavor)) {
             return false;
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java b/chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java
index 2089a3b..f1cdf13 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java
@@ -12,13 +12,20 @@ import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.StrictMode;
 import android.os.UserManager;
 import android.speech.RecognizerIntent;
+import android.text.TextUtils;
 
+import org.chromium.base.ApplicationStatus;
 import org.chromium.base.CommandLine;
+import org.chromium.base.FieldTrialList;
+import org.chromium.base.Log;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.browser.ChromeSwitches;
+import org.chromium.chrome.browser.ChromeVersionInfo;
+import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
 import org.chromium.chrome.browser.preferences.DocumentModeManager;
 import org.chromium.sync.signin.AccountManagerHelper;
 import org.chromium.ui.base.DeviceFormFactor;
@@ -30,9 +37,17 @@ import java.util.List;
  * this device.
  */
 public class FeatureUtilities {
+    private static final String TAG = "FeatureUtilities";
+    private static final String HERB_EXPERIMENT_NAME = "TabManagementExperiment";
+    private static final String HERB_EXPERIMENT_FLAVOR_PARAM = "type";
+
     private static Boolean sHasGoogleAccountAuthenticator;
     private static Boolean sHasRecognitionIntentHandler;
     private static Boolean sDocumentModeDisabled;
+
+    private static String sCachedHerbFlavor;
+    private static boolean sIsHerbFlavorCached;
+
     /** Used to track if cached command line flags should be refreshed. */
     private static CommandLine.ResetListener sResetListener = null;
 
@@ -171,6 +186,83 @@ public class FeatureUtilities {
         CommandLine.addResetListener(sResetListener);
     }
 
+    /**
+     * @return Which flavor of Herb is being tested.  See {@link ChromeSwitches#HERB_FLAVOR_ANISE}
+     *         and its related switches.
+     */
+    public static String getHerbFlavor() {
+        if (!sIsHerbFlavorCached) {
+            sCachedHerbFlavor = null;
+
+            Context context = ApplicationStatus.getApplicationContext();
+            if (isDocumentMode(context) || ChromeVersionInfo.isStableBuild()
+                    || ChromeVersionInfo.isBetaBuild() || DeviceFormFactor.isTablet(context)) {
+                // Disable Herb.
+                sCachedHerbFlavor = ChromeSwitches.HERB_FLAVOR_DISABLED;
+            } else {
+                // Allowing disk access for preferences while prototyping.
+                StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
+                try {
+                    sCachedHerbFlavor =
+                            ChromePreferenceManager.getInstance(context).getCachedHerbFlavor();
+                } finally {
+                    StrictMode.setThreadPolicy(oldPolicy);
+                }
+            }
+
+            sIsHerbFlavorCached = true;
+            Log.d(TAG, "Retrieved cached Herb flavor: " + sCachedHerbFlavor);
+        }
+
+        return sCachedHerbFlavor;
+    }
+
+    /**
+     * Caches which flavor of Herb the user prefers from native.
+     */
+    public static void cacheHerbFlavor() {
+        String oldFlavor = getHerbFlavor();
+
+        // Check the experiment value before the command line to put the user in the correct group.
+        // The first clause does the null checks so so we can freely use the startsWith() function.
+        String newFlavor = FieldTrialList.findFullName(HERB_EXPERIMENT_NAME);
+        Log.d(TAG, "Experiment flavor: " + newFlavor);
+        if (TextUtils.isEmpty(newFlavor)
+                || newFlavor.startsWith(ChromeSwitches.HERB_FLAVOR_CONTROL)
+                || newFlavor.startsWith(ChromeSwitches.HERB_FLAVOR_DEFAULT)) {
+            newFlavor = ChromeSwitches.HERB_FLAVOR_DISABLED;
+        } else if (newFlavor.startsWith(ChromeSwitches.HERB_FLAVOR_ANISE)) {
+            newFlavor = ChromeSwitches.HERB_FLAVOR_ANISE;
+        } else if (newFlavor.startsWith(ChromeSwitches.HERB_FLAVOR_BASIL)) {
+            newFlavor = ChromeSwitches.HERB_FLAVOR_BASIL;
+        } else if (newFlavor.startsWith(ChromeSwitches.HERB_FLAVOR_CHIVE)) {
+            newFlavor = ChromeSwitches.HERB_FLAVOR_CHIVE;
+        } else if (newFlavor.startsWith(ChromeSwitches.HERB_FLAVOR_DILL)) {
+            newFlavor = ChromeSwitches.HERB_FLAVOR_DILL;
+        }
+
+        CommandLine instance = CommandLine.getInstance();
+        if (instance.hasSwitch(ChromeSwitches.HERB_FLAVOR_DISABLED_SWITCH)) {
+            newFlavor = ChromeSwitches.HERB_FLAVOR_DISABLED;
+        } else if (instance.hasSwitch(ChromeSwitches.HERB_FLAVOR_ANISE_SWITCH)) {
+            newFlavor = ChromeSwitches.HERB_FLAVOR_ANISE;
+        } else if (instance.hasSwitch(ChromeSwitches.HERB_FLAVOR_BASIL_SWITCH)) {
+            newFlavor = ChromeSwitches.HERB_FLAVOR_BASIL;
+        } else if (instance.hasSwitch(ChromeSwitches.HERB_FLAVOR_CHIVE_SWITCH)) {
+            newFlavor = ChromeSwitches.HERB_FLAVOR_CHIVE;
+        } else if (instance.hasSwitch(ChromeSwitches.HERB_FLAVOR_DILL_SWITCH)) {
+            newFlavor = ChromeSwitches.HERB_FLAVOR_DILL;
+        }
+
+        Log.d(TAG, "Caching flavor: " + newFlavor);
+        sCachedHerbFlavor = newFlavor;
+
+        if (!TextUtils.equals(oldFlavor, newFlavor)) {
+            Context context = ApplicationStatus.getApplicationContext();
+            ChromePreferenceManager.getInstance(context).setCachedHerbFlavor(newFlavor);
+        }
+    }
+
     private static native void nativeSetDocumentModeEnabled(boolean enabled);
     private static native void nativeSetCustomTabVisible(boolean visible);
     public static native void nativeSetSqlMmapDisabledByDefault();
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index b5502ed..b1dbcce 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -528,15 +528,17 @@ const FeatureEntry::Choice kEnableOfflinePagesChoices[] = {
 };
 
 const FeatureEntry::Choice kHerbPrototypeChoices[] = {
-    {IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED, "", ""},
+    {IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", ""},
+    {IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+     switches::kTabManagementExperimentTypeDisabled, ""},
     {IDS_FLAGS_HERB_PROTOTYPE_FLAVOR_ANISE,
-     switches::kTabManagementExperimentType, "anise"},
+     switches::kTabManagementExperimentTypeAnise, ""},
     {IDS_FLAGS_HERB_PROTOTYPE_FLAVOR_BASIL,
-     switches::kTabManagementExperimentType, "basil"},
+     switches::kTabManagementExperimentTypeBasil, ""},
     {IDS_FLAGS_HERB_PROTOTYPE_FLAVOR_CHIVE,
-     switches::kTabManagementExperimentType, "chive"},
+     switches::kTabManagementExperimentTypeChive, ""},
     {IDS_FLAGS_HERB_PROTOTYPE_FLAVOR_DILL,
-     switches::kTabManagementExperimentType, "dill"},
+     switches::kTabManagementExperimentTypeDill, ""},
 };
 #endif  // defined(OS_ANDROID)
 
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 53b8509..b1be5b9 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1318,7 +1318,16 @@ const char kForceShowUpdateMenuBadge[] = "force-show-update-menu-badge";
 const char kMarketUrlForTesting[] = "market-url-for-testing";
 
 // Specifies a particular tab management experiment to enable.
-const char kTabManagementExperimentType[] = "tab-management-experiment-type";
+const char kTabManagementExperimentTypeDisabled[] =
+    "tab-management-experiment-type-disabled";
+const char kTabManagementExperimentTypeAnise[] =
+    "tab-management-experiment-type-anise";
+const char kTabManagementExperimentTypeBasil[] =
+    "tab-management-experiment-type-basil";
+const char kTabManagementExperimentTypeChive[] =
+    "tab-management-experiment-type-chive";
+const char kTabManagementExperimentTypeDill[] =
+    "tab-management-experiment-type-dill";
 #endif  // defined(OS_ANDROID)
 
 #if defined(OS_WIN) || defined(OS_LINUX)
diff --git a/chrome/common/chrome_switches.h b/chrome/common/chrome_switches.h
index 03ad823..c3fb63f 100644
--- a/chrome/common/chrome_switches.h
+++ b/chrome/common/chrome_switches.h
@@ -306,7 +306,11 @@ extern const char kForceShowUpdateMenuItemNewFeaturesSummary[];
 extern const char kForceShowUpdateMenuItemCustomSummary[];
 extern const char kForceShowUpdateMenuBadge[];
 extern const char kMarketUrlForTesting[];
-extern const char kTabManagementExperimentType[];
+extern const char kTabManagementExperimentTypeDisabled[];
+extern const char kTabManagementExperimentTypeAnise[];
+extern const char kTabManagementExperimentTypeBasil[];
+extern const char kTabManagementExperimentTypeChive[];
+extern const char kTabManagementExperimentTypeDill[];
 #endif  // defined(OS_ANDROID)
 
 #if defined(USE_ASH)
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 4469a7b..c9c910a 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -71411,6 +71411,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="-1497338981" label="disable-accelerated-overflow-scroll"/>
   <int value="-1490298774" label="enable-captive-portal-bypass-proxy-option"/>
   <int value="-1482685863" label="enable-request-tablet-site"/>
+  <int value="-1467332609" label="tab-management-experiment-type-anise"/>
   <int value="-1460462432" label="disable-media-source"/>
   <int value="-1440152291" label="disable-gesture-typing"/>
   <int value="-1433719718" label="enable-webrtc-stun-origin"/>
@@ -71565,6 +71566,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="-340622848" label="disable-javascript-harmony-shipping"/>
   <int value="-340255045" label="allow-nacl-socket-api"/>
   <int value="-328361990" label="enable-experimental-extension-apis"/>
+  <int value="-322827131" label="tab-management-experiment-type-basil"/>
   <int value="-320820051" label="enable-zero-copy"/>
   <int value="-314910380" label="disable-distance-field-text"/>
   <int value="-311148335" label="v8-pac-mojo-out-of-process"/>
@@ -71692,6 +71694,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="773919225" label="disable-office-editing-component-extension"/>
   <int value="779086132" label="enable-data-reduction-proxy-alt"/>
   <int value="782167080" label="enable-new-qp-input-view"/>
+  <int value="807734471" label="tab-management-experiment-type-disabled"/>
   <int value="811374216" label="disable-new-bookmark-apps"/>
   <int value="820650704" label="disable-ntp-popular-sites"/>
   <int value="821192723" label="show-fps-counter"/>
@@ -71740,6 +71743,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="1105439588" label="enable-swipe-selection"/>
   <int value="1107543566" label="enable-one-copy"/>
   <int value="1108663108" label="disable-device-discovery-notifications"/>
+  <int value="1113365156" label="tab-management-experiment-type-chive"/>
   <int value="1114629582" label="enable-floating-virtual-keyboard"/>
   <int value="1118109174" label="enable-launcher-search-provider-api"/>
   <int value="1129888794" label="ash-touch-hud"/>
@@ -71874,6 +71878,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="1993258379" label="enable-icon-ntp"/>
   <int value="2000091128" label="enable-touch-hover"/>
   <int value="2004829262" label="enable-webgl-draft-extensions"/>
+  <int value="2005614493" label="tab-management-experiment-type-dill"/>
   <int value="2037756154" label="enable-impl-side-painting"/>
   <int value="2059322877" label="new-avatar-menu"/>
   <int value="2071461362" label="disable-credit-card-scan"/>
diff --git a/ui/android/java/strings/android_ui_strings.grd b/ui/android/java/strings/android_ui_strings.grd
index 1eee849..1ce51bc 100644
--- a/ui/android/java/strings/android_ui_strings.grd
+++ b/ui/android/java/strings/android_ui_strings.grd
@@ -234,11 +234,6 @@
       <message name="IDS_AUTOFILL_KEYBOARD_ACCESSORY_CONTENT_DESCRIPTION" desc="The text announced by the screen reader when the autofill suggestions are shown.">
         Suggestions available
       </message>
-      
-      <!-- Herb strings -->
-      <message name="IDS_CACHE_NATIVE_FLAGS_REQUIRES_RESTART" desc="Toast telling the user that flags may not take effect until a restart." translateable="false">
-        Cached flags may not take effect until the browser is restarted again.
-      </message>
     </messages>
   </release>
 </grit>