AW: remove Variations.AppSeedRequestState histogram

No change to behavior. This removes the Variations.AppSeedRequestState
histogram and the associated tests.

Fixed: 1130651
Test: run_webview_instrumentation_test_apk -f *Variations*
Change-Id: If7102fe04758c864e00cadd671fc4875af98322a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2491184
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Commit-Queue: Mark Pearson <mpearson@chromium.org>
Auto-Submit: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Changwan Ryu <changwan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819951}

android_webview/java/src/org/chromium/android_webview/variations/VariationsSeedLoader.java

@@ -15,7 +15,6 @@ import android.os.ParcelFileDescriptor;
 import android.os.RemoteException;
 import android.os.SystemClock;
 
-import androidx.annotation.IntDef;
 import androidx.annotation.VisibleForTesting;
 
 import org.chromium.android_webview.AwBrowserProcess;
@@ -35,8 +34,6 @@ import org.chromium.components.variations.LoadSeedResult;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
 import java.util.Date;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.FutureTask;
@@ -92,9 +89,6 @@ public class VariationsSeedLoader {
     @VisibleForTesting
     public static final String APP_SEED_FRESHNESS_HISTOGRAM_NAME = "Variations.AppSeedFreshness";
     @VisibleForTesting
-    public static final String APP_SEED_REQUEST_STATE_HISTOGRAM_NAME =
-            "Variations.AppSeedRequestState";
-    @VisibleForTesting
     public static final String DOWNLOAD_JOB_FETCH_RESULT_HISTOGRAM_NAME =
             "Variations.WebViewDownloadJobFetchResult";
     @VisibleForTesting
@@ -114,23 +108,6 @@ public class VariationsSeedLoader {
     private SeedLoadAndUpdateRunnable mRunnable;
     private SeedServerCallback mSeedServerCallback = new SeedServerCallback();
 
-    // UMA histogram values for the result of checking if the app needs a new variations seed.
-    // Keep in sync with AppSeedRequestState enum in enums.xml.
-    //
-    // These values are persisted to logs. Entries should not be renumbered and
-    // numeric values should never be reused.
-    @IntDef({AppSeedRequestState.UNKNOWN, AppSeedRequestState.SEED_FRESH,
-            AppSeedRequestState.SEED_REQUESTED, AppSeedRequestState.SEED_REQUEST_THROTTLED})
-    @Retention(RetentionPolicy.SOURCE)
-    @VisibleForTesting
-    public @interface AppSeedRequestState {
-        int UNKNOWN = 0;
-        int SEED_FRESH = 1;
-        int SEED_REQUESTED = 2;
-        int SEED_REQUEST_THROTTLED = 3;
-        int NUM_ENTRIES = 4;
-    }
-
     private static void recordLoadSeedResult(@LoadSeedResult int result) {
         RecordHistogram.recordEnumeratedHistogram(
                 SEED_LOAD_RESULT_HISTOGRAM_NAME, result, LoadSeedResult.ENUM_SIZE);
@@ -140,11 +117,6 @@ public class VariationsSeedLoader {
         RecordHistogram.recordTimesHistogram(SEED_LOAD_BLOCKING_TIME_HISTOGRAM_NAME, timeMs);
     }
 
-    private static void recordSeedRequestState(@AppSeedRequestState int state) {
-        RecordHistogram.recordEnumeratedHistogram(
-                APP_SEED_REQUEST_STATE_HISTOGRAM_NAME, state, AppSeedRequestState.NUM_ENTRIES);
-    }
-
     private static void recordAppSeedFreshness(long freshnessMinutes) {
         // Bucket parameters should match Variations.SeedFreshness.
         // See variations::RecordSeedFreshness.
@@ -185,12 +157,10 @@ public class VariationsSeedLoader {
         //   epoch, or Long.MIN_VALUE if we have no seed. This value originates from the server.
         // - mSeedFileTime: The time, in milliseconds since the UNIX epoch, our local copy of the
         //   seed was last written to disk as measured by the device's clock.
-        // - mSeedRequestState: The result of checking if a new seed is required.
         private boolean mFoundNewSeed;
         private boolean mNeedNewSeed;
         private long mCurrentSeedDate = Long.MIN_VALUE;
         private long mSeedFileTime;
-        private int mSeedRequestState = AppSeedRequestState.UNKNOWN;
 
         private boolean parseSeedFile(File seedFile) {
             if (!VariationsSeedLoaderJni.get().parseAndSaveSeedProto(seedFile.getPath())) {
@@ -222,15 +192,11 @@ public class VariationsSeedLoader {
             // avoid delaying FutureTask.get().)
             if (!loadedSeed || isSeedExpired(mSeedFileTime)) {
                 mNeedNewSeed = true;
-                mSeedRequestState = AppSeedRequestState.SEED_REQUESTED;
 
                 // Rate-limit the requests.
                 if (shouldThrottleRequests(getCurrentTimeMillis())) {
                     mNeedNewSeed = false;
-                    mSeedRequestState = AppSeedRequestState.SEED_REQUEST_THROTTLED;
                 }
-            } else {
-                mSeedRequestState = AppSeedRequestState.SEED_FRESH;
             }
 
             // Save the date field of whatever seed was loaded, if any.
@@ -266,7 +232,6 @@ public class VariationsSeedLoader {
         public boolean get(long timeout, TimeUnit unit)
                 throws InterruptedException, ExecutionException, TimeoutException {
             boolean success = mLoadTask.get(timeout, unit);
-            recordSeedRequestState(mSeedRequestState);
             if (mSeedFileTime != 0) {
                 long freshnessMinutes =
                         TimeUnit.MILLISECONDS.toMinutes(getCurrentTimeMillis() - mSeedFileTime);

android_webview/javatests/src/org/chromium/android_webview/test/VariationsSeedLoaderTest.java

@@ -164,18 +164,6 @@ public class VariationsSeedLoaderTest {
                 RecordHistogram.getHistogramValueCountForTesting(histogramName, expectedValue * 2));
     }
 
-    private void assertNoAppSeedRequestStateValues() {
-        Assert.assertEquals(0,
-                RecordHistogram.getHistogramTotalCountForTesting(
-                        VariationsSeedLoader.APP_SEED_REQUEST_STATE_HISTOGRAM_NAME));
-    }
-
-    private void assertSingleAppSeedRequestStateValue(
-            @VariationsSeedLoader.AppSeedRequestState int state) {
-        assertSingleRecordInHistogram(
-                VariationsSeedLoader.APP_SEED_REQUEST_STATE_HISTOGRAM_NAME, state);
-    }
-
     // Test the case that:
     // VariationsUtils.getSeedFile() - doesn't exist
     // VariationsUtils.getNewSeedFile() - doesn't exist
@@ -364,74 +352,6 @@ public class VariationsSeedLoaderTest {
         }
     }
 
-    // Test we record the Variations.AppSeedRequestState metric when the seed is fresh.
-    @Test
-    @MediumTest
-    public void testRecordSeedFresh() throws Exception {
-        File oldFile = VariationsUtils.getSeedFile();
-        Assert.assertTrue("Expected seed file to not already exist", oldFile.createNewFile());
-        VariationsTestUtils.writeMockSeed(oldFile);
-        oldFile.setLastModified(CURRENT_TIME_MILLIS);
-        assertNoAppSeedRequestStateValues();
-
-        runTestLoaderBlocking();
-
-        assertSingleAppSeedRequestStateValue(VariationsSeedLoader.AppSeedRequestState.SEED_FRESH);
-    }
-
-    // Test we record the Variations.AppSeedRequestState metric when a new seed is requested.
-    @Test
-    @MediumTest
-    public void testRecordSeedRequested() throws Exception {
-        File oldFile = VariationsUtils.getSeedFile();
-        Assert.assertTrue("Expected seed file to not already exist", oldFile.createNewFile());
-        VariationsTestUtils.writeMockSeed(oldFile);
-        oldFile.setLastModified(EXPIRED_TIMESTAMP);
-        assertNoAppSeedRequestStateValues();
-
-        runTestLoaderBlocking();
-
-        assertSingleAppSeedRequestStateValue(
-                VariationsSeedLoader.AppSeedRequestState.SEED_REQUESTED);
-    }
-
-    // Test we record the Variations.AppSeedRequestState metric when a seed request is throttled.
-    @Test
-    @MediumTest
-    public void testRecordSeedRequestThrottled() throws Exception {
-        File oldFile = VariationsUtils.getSeedFile();
-        Assert.assertTrue("Expected seed file to not already exist", oldFile.createNewFile());
-        VariationsTestUtils.writeMockSeed(oldFile);
-        oldFile.setLastModified(EXPIRED_TIMESTAMP);
-        // Update the last modified time of the stamp file to simulate having just requested a
-        // new seed from the service.
-        VariationsUtils.updateStampTime();
-        assertNoAppSeedRequestStateValues();
-
-        runTestLoaderBlocking();
-
-        assertSingleAppSeedRequestStateValue(
-                VariationsSeedLoader.AppSeedRequestState.SEED_REQUEST_THROTTLED);
-    }
-
-    // Test we record the Variations.AppSeedFreshness metric with loading a seed.
-    @Test
-    @MediumTest
-    public void testRecordAppSeedFreshness() throws Exception {
-        long seedAgeHours = 2;
-        File oldFile = VariationsUtils.getSeedFile();
-        Assert.assertTrue("Expected seed file to not already exist", oldFile.createNewFile());
-        VariationsTestUtils.writeMockSeed(oldFile);
-        oldFile.setLastModified(CURRENT_TIME_MILLIS - TimeUnit.HOURS.toMillis(seedAgeHours));
-
-        runTestLoaderBlocking();
-
-        Assert.assertEquals(1,
-                RecordHistogram.getHistogramValueCountForTesting(
-                        VariationsSeedLoader.APP_SEED_FRESHNESS_HISTOGRAM_NAME,
-                        (int) TimeUnit.HOURS.toMinutes(seedAgeHours)));
-    }
-
     // Tests that the finch-seed-expiration-age flag works.
     @Test
     @MediumTest

tools/metrics/histograms/enums.xml

@@ -3101,6 +3101,9 @@ Unknown properties are collapsed to zero. -->
 </enum>
 
 <enum name="AppSeedRequestState">
+  <obsolete>
+    Removed from code October 2020.
+  </obsolete>
   <int value="0" label="Unknown seed state"/>
   <int value="1" label="Current seed fresh"/>
   <int value="2" label="New seed requested from the service"/>

tools/metrics/histograms/histograms_xml/variations/histograms.xml

@@ -39,6 +39,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Variations.AppSeedRequestState" enum="AppSeedRequestState"
     expires_after="2020-11-01">
+  <obsolete>
+    Removed from code October 2020.
+  </obsolete>
   <owner>rmcelrath@chromium.org</owner>
   <owner>ntfschr@chromium.org</owner>
   <owner>src/android_webview/OWNERS</owner>