Stop clearing KEY_PERSISTED_NOTIFICATION_ID SharedPref.

Move it to deprecated keys, which reserves to name to prevent reuse.

Bug: 1022108

Change-Id: Iff335c71208327c0960592ab058cfc3b83344265
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1993495Reviewed-by: Min Qin <qinmin@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735566}

chrome/android/java/src/org/chromium/chrome/browser/download/DownloadForegroundService.java

@@ -32,8 +32,6 @@ import java.lang.annotation.RetentionPolicy;
  */
 public class DownloadForegroundService extends Service {
     private static final String TAG = "DownloadFg";
-    // Deprecated, remove this after M75.
-    private static final String KEY_PERSISTED_NOTIFICATION_ID = "PersistedNotificationId";
     private final IBinder mBinder = new LocalBinder();
 
     private NotificationManager mNotificationManager;
@@ -52,7 +50,6 @@ public class DownloadForegroundService extends Service {
         mNotificationManager =
                 (NotificationManager) ContextUtils.getApplicationContext().getSystemService(
                         Context.NOTIFICATION_SERVICE);
-        clearPersistedNotificationId();
     }
 
     /**
@@ -224,15 +221,6 @@ public class DownloadForegroundService extends Service {
         }
     }
 
-
-    /**
-     * Clear stored value for the id of the notification pinned to the service.
-     */
-    @VisibleForTesting
-    static void clearPersistedNotificationId() {
-        ContextUtils.getAppSharedPreferences().edit().remove(KEY_PERSISTED_NOTIFICATION_ID).apply();
-    }
-
     /** Methods for testing. */
 
     @VisibleForTesting

chrome/android/javatests/src/org/chromium/chrome/browser/download/DownloadForegroundServiceTest.java

@@ -9,7 +9,6 @@ import static android.app.Service.STOP_FOREGROUND_REMOVE;
 
 import static junit.framework.Assert.assertEquals;
 
-import static org.chromium.chrome.browser.download.DownloadForegroundService.clearPersistedNotificationId;
 import static org.chromium.chrome.browser.download.DownloadSnackbarController.INVALID_NOTIFICATION_ID;
 
 import android.app.Notification;
@@ -18,7 +17,6 @@ import android.support.v4.app.ServiceCompat;
 
 import androidx.annotation.IntDef;
 
-import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -106,7 +104,6 @@ public class DownloadForegroundServiceTest {
     @Before
     public void setUp() {
         mForegroundService = new MockDownloadForegroundService();
-        clearPersistedNotificationId();
         mNotification =
                 NotificationBuilderFactory
                         .createChromeNotificationBuilder(
@@ -117,11 +114,6 @@ public class DownloadForegroundServiceTest {
                         .build();
     }
 
-    @After
-    public void tearDown() {
-        clearPersistedNotificationId();
-    }
-
     /**
      * The expected behavior for start foreground when the API >= 24 is that the old notification is
      * able to be detached and the new notification pinned without any need for relaunching or

chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceKeys.java

@@ -670,6 +670,7 @@ public final class ChromePreferenceKeys {
     static List<String> createDeprecatedKeysForTesting() {
         // clang-format off
         return Arrays.asList(
+                "PersistedNotificationId",
                 "PhysicalWeb.ActivityReferral",
                 "PhysicalWeb.HasDeferredMetrics",
                 "PhysicalWeb.OptIn.DeclineButtonPressed",