Clean up expired histogram "Settings.*Home*"

Removed histogram:
- Settings.HomePageIsCustomized
- Settings.ShowHomeButtonPreferenceState*

Bug: 1109958, 1138318
Change-Id: I7dee5c0c3c4e59271f4df929e849f92033e5ccc0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2472431
Commit-Queue: Wenyu Fu <wenyufu@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Auto-Submit: Wenyu Fu <wenyufu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818033}

chrome/android/java/src/org/chromium/chrome/browser/homepage/HomepageManager.java

@@ -12,9 +12,6 @@ import androidx.annotation.VisibleForTesting;
 import org.chromium.base.ObserverList;
 import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.base.metrics.RecordUserAction;
-import org.chromium.chrome.browser.flags.CachedFeatureFlags;
-import org.chromium.chrome.browser.flags.ChromeFeatureList;
-import org.chromium.chrome.browser.homepage.settings.HomepageMetricsEnums.HomeButtonPreferenceState;
 import org.chromium.chrome.browser.homepage.settings.HomepageMetricsEnums.HomepageLocationType;
 import org.chromium.chrome.browser.ntp.NewTabPage;
 import org.chromium.chrome.browser.partnercustomizations.PartnerBrowserCustomizations;
@@ -175,9 +172,6 @@ public class HomepageManager implements HomepagePolicyManager.HomepagePolicyStat
      */
     public void setPrefHomepageEnabled(boolean enabled) {
         mSharedPreferencesManager.writeBoolean(ChromePreferenceKeys.HOMEPAGE_ENABLED, enabled);
-        RecordHistogram.recordBooleanHistogram(
-                "Settings.ShowHomeButtonPreferenceStateChanged", enabled);
-        recordHomeButtonPreferenceState();
         notifyHomepageUpdated();
     }
 
@@ -238,7 +232,6 @@ public class HomepageManager implements HomepagePolicyManager.HomepagePolicyStat
         }
 
         if (wasUseDefaultUri != useDefaultUri) {
-            recordHomepageIsCustomized(!useDefaultUri);
             mSharedPreferencesManager.writeBoolean(
                     ChromePreferenceKeys.HOMEPAGE_USE_DEFAULT_URI, useDefaultUri);
         }
@@ -252,31 +245,6 @@ public class HomepageManager implements HomepagePolicyManager.HomepagePolicyStat
         notifyHomepageUpdated();
     }
 
-    /**
-     * Get the homepage button preference state.
-     */
-    public static void recordHomeButtonPreferenceState() {
-        if (!CachedFeatureFlags.isEnabled(ChromeFeatureList.HOMEPAGE_LOCATION_POLICY)) {
-            RecordHistogram.recordBooleanHistogram(
-                    "Settings.ShowHomeButtonPreferenceState", HomepageManager.isHomepageEnabled());
-            return;
-        }
-
-        int state = HomeButtonPreferenceState.USER_DISABLED;
-        if (HomepagePolicyManager.isHomepageManagedByPolicy()) {
-            state = HomeButtonPreferenceState.MANAGED_ENABLED;
-        } else if (isHomepageEnabled()) {
-            state = HomeButtonPreferenceState.USER_ENABLED;
-        }
-
-        RecordHistogram.recordEnumeratedHistogram("Settings.ShowHomeButtonPreferenceStateManaged",
-                state, HomeButtonPreferenceState.NUM_ENTRIES);
-    }
-
-    public static void recordHomepageIsCustomized(boolean isCustomized) {
-        RecordHistogram.recordBooleanHistogram("Settings.HomePageIsCustomized", isCustomized);
-    }
-
     /**
      * Record histogram "Settings.Homepage.LocationType" with the current homepage location type.
      */
@@ -320,11 +288,6 @@ public class HomepageManager implements HomepagePolicyManager.HomepagePolicyStat
     @Override
     public void onHomepagePolicyUpdate() {
         notifyHomepageUpdated();
-
-        boolean isPolicyEnabled = HomepagePolicyManager.isHomepageManagedByPolicy();
-        if (isPolicyEnabled) {
-            recordHomepageIsCustomized(false);
-        }
     }
 
     @Override

chrome/android/java/src/org/chromium/chrome/browser/homepage/settings/HomepageMetricsEnums.java

@@ -15,25 +15,6 @@ import java.lang.annotation.RetentionPolicy;
 public final class HomepageMetricsEnums {
     private HomepageMetricsEnums() {}
 
-    /**
-     * Possible states for HomeButton. Used for Histogram
-     * Settings.ShowHomeButtonPreferenceStateManaged. Currently {@link
-     * HomeButtonPreferenceState.MANAGED_DISABLED } is not used.
-     *
-     * These values are persisted to logs, and should therefore never be renumbered nor reused.
-     */
-    @IntDef({HomeButtonPreferenceState.USER_DISABLED, HomeButtonPreferenceState.USER_ENABLED,
-            HomeButtonPreferenceState.MANAGED_DISABLED, HomeButtonPreferenceState.MANAGED_ENABLED})
-    @Retention(RetentionPolicy.SOURCE)
-    public @interface HomeButtonPreferenceState {
-        int USER_DISABLED = 0;
-        int USER_ENABLED = 1;
-        int MANAGED_DISABLED = 2;
-        int MANAGED_ENABLED = 3;
-
-        int NUM_ENTRIES = 4;
-    }
-
     /**
      * Possible location type for homepage. Used for Histogram "Settings.Homepage.LocationType"
      * recorded in {@link HomepageManager#recordHomepageLocationType()}.

chrome/android/java/src/org/chromium/chrome/browser/init/ProcessInitializationHandler.java

@@ -342,8 +342,6 @@ public class ProcessInitializationHandler {
         deferredStartupHandler.addDeferredTask(new Runnable() {
             @Override
             public void run() {
-                HomepageManager.recordHomeButtonPreferenceState();
-                HomepageManager.recordHomepageIsCustomized(HomepageManager.isHomepageCustomized());
                 HomepageManager.recordHomepageLocationTypeIfEnabled();
             }
         });

chrome/android/javatests/src/org/chromium/chrome/browser/homepage/HomepagePolicyIntegrationTest.java

@@ -28,7 +28,6 @@ import org.chromium.base.test.util.FlakyTest;
 import org.chromium.chrome.browser.ChromeTabbedActivity;
 import org.chromium.chrome.browser.flags.ChromeFeatureList;
 import org.chromium.chrome.browser.flags.ChromeSwitches;
-import org.chromium.chrome.browser.homepage.settings.HomepageMetricsEnums.HomeButtonPreferenceState;
 import org.chromium.chrome.browser.homepage.settings.HomepageMetricsEnums.HomepageLocationType;
 import org.chromium.chrome.browser.homepage.settings.HomepageSettings;
 import org.chromium.chrome.browser.preferences.ChromePreferenceKeys;
@@ -67,9 +66,6 @@ public class HomepagePolicyIntegrationTest {
     public static final String TEST_URL = "http://127.0.0.1:8000/foo.html";
     public static final String GOOGLE_HTML = "/chrome/test/data/android/google.html";
 
-    private static final String METRICS_HOME_BUTTON_STATE_ENUM =
-            "Settings.ShowHomeButtonPreferenceStateManaged";
-    private static final String METRICS_HOMEPAGE_IS_CUSTOMIZED = "Settings.HomePageIsCustomized";
     private static final String METRICS_HOMEPAGE_LOCATION_TYPE = "Settings.Homepage.LocationType";
 
     private EmbeddedTestServer mTestServer;
@@ -119,18 +115,6 @@ public class HomepagePolicyIntegrationTest {
                 SharedPreferencesManager.getInstance().readString(
                         ChromePreferenceKeys.HOMEPAGE_LOCATION_POLICY, ""));
 
-        // METRICS_HOMEPAGE_IS_CUSTOMIZED Should be collected twice it is called in:
-        // 1. ProcessInitializationHandler#handleDeferredStartupTasksInitialization;
-        // 2. HomepageManager#onHomepagePolicyUpdate, which will be called when native initialized.
-        Assert.assertEquals(
-                "Settings.HomepageIsCustomized should be recorded twice when policy enabled", 2,
-                RecordHistogram.getHistogramTotalCountForTesting(METRICS_HOMEPAGE_IS_CUSTOMIZED));
-
-        // METRICS_HOME_BUTTON_STATE_ENUM should be collected once in deferred start up tasks.
-        Assert.assertEquals(1,
-                RecordHistogram.getHistogramValueCountForTesting(
-                        METRICS_HOME_BUTTON_STATE_ENUM, HomeButtonPreferenceState.MANAGED_ENABLED));
-
         // METRICS_HOMEPAGE_LOCATION_TYPE is recorded once in deferred start up tasks.
         Assert.assertEquals("Settings.Homepage.LocationType should record POLICY_OTHER once.", 1,
                 RecordHistogram.getHistogramValueCountForTesting(

tools/metrics/histograms/enums.xml

@@ -35971,6 +35971,9 @@ Called by update_gpu_driver_bug_workaround_entries.py.-->
 </enum>
 
 <enum name="HomeButtonPreferenceStateType">
+  <obsolete>
+    Removed from code as of 10/2020.
+  </obsolete>
   <int value="0" label="User Disabled"/>
   <int value="1" label="User Enabled"/>
   <int value="2" label="Managed Disabled"/>

tools/metrics/histograms/histograms_xml/settings/histograms.xml

@@ -85,6 +85,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Settings.HomePageIsCustomized" enum="Boolean"
     expires_after="2020-08-28">
+  <obsolete>
+    Expired and removed from code as of 10/2020.
+  </obsolete>
   <owner>twellington@chromium.org</owner>
   <owner>tedchoc@chromium.org</owner>
   <summary>
@@ -272,6 +275,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Settings.ShowHomeButtonPreferenceState" enum="BooleanEnabled"
     expires_after="M85">
+  <obsolete>
+    Expired and removed from code as of 10/2020.
+  </obsolete>
   <owner>twellington@chromium.org</owner>
   <owner>tedchoc@chromium.org</owner>
   <summary>
@@ -287,6 +293,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Settings.ShowHomeButtonPreferenceStateChanged"
     enum="BooleanEnabled" expires_after="M88">
+  <obsolete>
+    Removed from code as of 10/2020.
+  </obsolete>
   <owner>twellington@chromium.org</owner>
   <owner>tedchoc@chromium.org</owner>
   <summary>
@@ -297,6 +306,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Settings.ShowHomeButtonPreferenceStateManaged"
     enum="HomeButtonPreferenceStateType" expires_after="M88">
+  <obsolete>
+    Removed from code as of 10/2020.
+  </obsolete>
   <owner>twellington@chromium.org</owner>
   <owner>tedchoc@chromium.org</owner>
   <summary>