diff --git a/java/com/google/gerrit/acceptance/ExtensionRegistry.java b/java/com/google/gerrit/acceptance/ExtensionRegistry.java
index c3823cd..9b7e455 100644
--- a/java/com/google/gerrit/acceptance/ExtensionRegistry.java
+++ b/java/com/google/gerrit/acceptance/ExtensionRegistry.java
@@ -16,8 +16,11 @@
 
 import com.google.gerrit.extensions.api.changes.ActionVisitor;
 import com.google.gerrit.extensions.config.DownloadScheme;
+import com.google.gerrit.extensions.events.AccountIndexedListener;
 import com.google.gerrit.extensions.events.ChangeIndexedListener;
 import com.google.gerrit.extensions.events.CommentAddedListener;
+import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
+import com.google.gerrit.extensions.events.GroupIndexedListener;
 import com.google.gerrit.extensions.events.ProjectIndexedListener;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.extensions.registration.DynamicSet;
@@ -37,7 +40,9 @@
 import java.util.List;
 
 public class ExtensionRegistry {
+  private final DynamicSet<AccountIndexedListener> accountIndexedListeners;
   private final DynamicSet<ChangeIndexedListener> changeIndexedListeners;
+  private final DynamicSet<GroupIndexedListener> groupIndexedListeners;
   private final DynamicSet<ProjectIndexedListener> projectIndexedListeners;
   private final DynamicSet<CommitValidationListener> commitValidationListeners;
   private final DynamicSet<ExceptionHook> exceptionHooks;
@@ -50,10 +55,13 @@
   private final DynamicMap<DownloadScheme> downloadSchemes;
   private final DynamicSet<RefOperationValidationListener> refOperationValidationListeners;
   private final DynamicSet<CommentAddedListener> commentAddedListeners;
+  private final DynamicSet<GitReferenceUpdatedListener> refUpdatedListeners;
 
   @Inject
   ExtensionRegistry(
+      DynamicSet<AccountIndexedListener> accountIndexedListeners,
       DynamicSet<ChangeIndexedListener> changeIndexedListeners,
+      DynamicSet<GroupIndexedListener> groupIndexedListeners,
       DynamicSet<ProjectIndexedListener> projectIndexedListeners,
       DynamicSet<CommitValidationListener> commitValidationListeners,
       DynamicSet<ExceptionHook> exceptionHooks,
@@ -65,8 +73,11 @@
       DynamicSet<ActionVisitor> actionVisitors,
       DynamicMap<DownloadScheme> downloadSchemes,
       DynamicSet<RefOperationValidationListener> refOperationValidationListeners,
-      DynamicSet<CommentAddedListener> commentAddedListeners) {
+      DynamicSet<CommentAddedListener> commentAddedListeners,
+      DynamicSet<GitReferenceUpdatedListener> refUpdatedListeners) {
+    this.accountIndexedListeners = accountIndexedListeners;
     this.changeIndexedListeners = changeIndexedListeners;
+    this.groupIndexedListeners = groupIndexedListeners;
     this.projectIndexedListeners = projectIndexedListeners;
     this.commitValidationListeners = commitValidationListeners;
     this.exceptionHooks = exceptionHooks;
@@ -79,19 +90,29 @@
     this.downloadSchemes = downloadSchemes;
     this.refOperationValidationListeners = refOperationValidationListeners;
     this.commentAddedListeners = commentAddedListeners;
+    this.refUpdatedListeners = refUpdatedListeners;
   }
 
   public Registration newRegistration() {
     return new Registration();
   }
 
+  @SuppressWarnings("FunctionalInterfaceClash")
   public class Registration implements AutoCloseable {
     private final List<RegistrationHandle> registrationHandles = new ArrayList<>();
 
+    public Registration add(AccountIndexedListener accountIndexedListener) {
+      return add(accountIndexedListeners, accountIndexedListener);
+    }
+
     public Registration add(ChangeIndexedListener changeIndexedListener) {
       return add(changeIndexedListeners, changeIndexedListener);
     }
 
+    public Registration add(GroupIndexedListener groupIndexedListener) {
+      return add(groupIndexedListeners, groupIndexedListener);
+    }
+
     public Registration add(ProjectIndexedListener projectIndexedListener) {
       return add(projectIndexedListeners, projectIndexedListener);
     }
@@ -140,6 +161,10 @@
       return add(commentAddedListeners, commentAddedListener);
     }
 
+    public Registration add(GitReferenceUpdatedListener refUpdatedListener) {
+      return add(refUpdatedListeners, refUpdatedListener);
+    }
+
     private <T> Registration add(DynamicSet<T> dynamicSet, T extension) {
       RegistrationHandle registrationHandle = dynamicSet.add("gerrit", extension);
       registrationHandles.add(registrationHandle);
diff --git a/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java b/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java
index 47bc7b3..1fdf3d6 100644
--- a/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/accounts/AccountIT.java
@@ -57,6 +57,8 @@
 import com.google.common.util.concurrent.AtomicLongMap;
 import com.google.common.util.concurrent.Runnables;
 import com.google.gerrit.acceptance.AbstractDaemonTest;
+import com.google.gerrit.acceptance.ExtensionRegistry;
+import com.google.gerrit.acceptance.ExtensionRegistry.Registration;
 import com.google.gerrit.acceptance.GerritConfig;
 import com.google.gerrit.acceptance.PushOneCommit;
 import com.google.gerrit.acceptance.Sandboxed;
@@ -189,7 +191,6 @@
 import org.eclipse.jgit.transport.RemoteRefUpdate;
 import org.eclipse.jgit.treewalk.TreeWalk;
 import org.junit.After;
-import org.junit.Before;
 import org.junit.Test;
 
 public class AccountIT extends AbstractDaemonTest {
@@ -207,8 +208,6 @@
 
   @Inject private @ServerInitiated Provider<AccountsUpdate> accountsUpdateProvider;
   @Inject private AccountIndexer accountIndexer;
-  @Inject private DynamicSet<AccountIndexedListener> accountIndexedListeners;
-  @Inject private DynamicSet<GitReferenceUpdatedListener> refUpdateListeners;
   @Inject private ExternalIdNotes.Factory extIdNotesFactory;
   @Inject private ExternalIds externalIds;
   @Inject private GitReferenceUpdated gitReferenceUpdated;
@@ -222,6 +221,7 @@
   @Inject private StalenessChecker stalenessChecker;
   @Inject private VersionedAuthorizedKeys.Accessor authorizedKeys;
   @Inject private PermissionBackend permissionBackend;
+  @Inject private ExtensionRegistry extensionRegistry;
 
   @Inject protected Emails emails;
 
@@ -236,37 +236,6 @@
 
   @Inject protected GroupOperations groupOperations;
 
-  private AccountIndexedCounter accountIndexedCounter;
-  private RegistrationHandle accountIndexEventCounterHandle;
-  private RefUpdateCounter refUpdateCounter;
-  private RegistrationHandle refUpdateCounterHandle;
-
-  @Before
-  public void addAccountIndexEventCounter() {
-    accountIndexedCounter = new AccountIndexedCounter();
-    accountIndexEventCounterHandle = accountIndexedListeners.add("gerrit", accountIndexedCounter);
-  }
-
-  @After
-  public void removeAccountIndexEventCounter() {
-    if (accountIndexEventCounterHandle != null) {
-      accountIndexEventCounterHandle.remove();
-    }
-  }
-
-  @Before
-  public void addRefUpdateCounter() {
-    refUpdateCounter = new RefUpdateCounter();
-    refUpdateCounterHandle = refUpdateListeners.add("gerrit", refUpdateCounter);
-  }
-
-  @After
-  public void removeRefUpdateCounter() {
-    if (refUpdateCounterHandle != null) {
-      refUpdateCounterHandle.remove();
-    }
-  }
-
   @After
   public void clearPublicKeyStore() throws Exception {
     try (Repository repo = repoManager.openRepository(allUsers)) {
@@ -315,11 +284,14 @@
 
   @Test
   public void createByAccountCreator() throws Exception {
-    Account.Id accountId = createByAccountCreator(1);
-    refUpdateCounter.assertRefUpdateFor(
-        RefUpdateCounter.projectRef(allUsers, RefNames.refsUsers(accountId)),
-        RefUpdateCounter.projectRef(allUsers, RefNames.REFS_EXTERNAL_IDS),
-        RefUpdateCounter.projectRef(allUsers, RefNames.REFS_SEQUENCES + Sequences.NAME_ACCOUNTS));
+    RefUpdateCounter refUpdateCounter = new RefUpdateCounter();
+    try (Registration registration = extensionRegistry.newRegistration().add(refUpdateCounter)) {
+      Account.Id accountId = createByAccountCreator(1);
+      refUpdateCounter.assertRefUpdateFor(
+          RefUpdateCounter.projectRef(allUsers, RefNames.refsUsers(accountId)),
+          RefUpdateCounter.projectRef(allUsers, RefNames.REFS_EXTERNAL_IDS),
+          RefUpdateCounter.projectRef(allUsers, RefNames.REFS_SEQUENCES + Sequences.NAME_ACCOUNTS));
+    }
   }
 
   @Test
@@ -338,42 +310,54 @@
   }
 
   private Account.Id createByAccountCreator(int expectedAccountReindexCalls) throws Exception {
-    String name = "foo";
-    TestAccount foo = accountCreator.create(name);
-    AccountInfo info = gApi.accounts().id(foo.id().get()).get();
-    assertThat(info.username).isEqualTo(name);
-    assertThat(info.name).isEqualTo(name);
-    accountIndexedCounter.assertReindexOf(foo, expectedAccountReindexCalls);
-    assertUserBranch(foo.id(), name, null);
-    return foo.id();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String name = "foo";
+      TestAccount foo = accountCreator.create(name);
+      AccountInfo info = gApi.accounts().id(foo.id().get()).get();
+      assertThat(info.username).isEqualTo(name);
+      assertThat(info.name).isEqualTo(name);
+      accountIndexedCounter.assertReindexOf(foo, expectedAccountReindexCalls);
+      assertUserBranch(foo.id(), name, null);
+      return foo.id();
+    }
   }
 
   @Test
   public void createAnonymousCowardByAccountCreator() throws Exception {
-    TestAccount anonymousCoward = accountCreator.create();
-    accountIndexedCounter.assertReindexOf(anonymousCoward);
-    assertUserBranchWithoutAccountConfig(anonymousCoward.id());
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestAccount anonymousCoward = accountCreator.create();
+      accountIndexedCounter.assertReindexOf(anonymousCoward);
+      assertUserBranchWithoutAccountConfig(anonymousCoward.id());
+    }
   }
 
   @Test
   public void create() throws Exception {
-    AccountInput input = new AccountInput();
-    input.username = "foo";
-    input.name = "Foo";
-    input.email = "foo@example.com";
-    AccountInfo accountInfo = gApi.accounts().create(input).get();
-    assertThat(accountInfo._accountId).isNotNull();
-    assertThat(accountInfo.username).isEqualTo(input.username);
-    assertThat(accountInfo.name).isEqualTo(input.name);
-    assertThat(accountInfo.email).isEqualTo(input.email);
-    assertThat(accountInfo.status).isNull();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      AccountInput input = new AccountInput();
+      input.username = "foo";
+      input.name = "Foo";
+      input.email = "foo@example.com";
+      AccountInfo accountInfo = gApi.accounts().create(input).get();
+      assertThat(accountInfo._accountId).isNotNull();
+      assertThat(accountInfo.username).isEqualTo(input.username);
+      assertThat(accountInfo.name).isEqualTo(input.name);
+      assertThat(accountInfo.email).isEqualTo(input.email);
+      assertThat(accountInfo.status).isNull();
 
-    Account.Id accountId = Account.id(accountInfo._accountId);
-    accountIndexedCounter.assertReindexOf(accountId, 1);
-    assertThat(externalIds.byAccount(accountId))
-        .containsExactly(
-            ExternalId.createUsername(input.username, accountId, null),
-            ExternalId.createEmail(accountId, input.email));
+      Account.Id accountId = Account.id(accountInfo._accountId);
+      accountIndexedCounter.assertReindexOf(accountId, 1);
+      assertThat(externalIds.byAccount(accountId))
+          .containsExactly(
+              ExternalId.createUsername(input.username, accountId, null),
+              ExternalId.createEmail(accountId, input.email));
+    }
   }
 
   @Test
@@ -517,69 +501,93 @@
 
   @Test
   public void get() throws Exception {
-    AccountInfo info = gApi.accounts().id("admin").get();
-    assertThat(info.name).isEqualTo("Administrator");
-    assertThat(info.email).isEqualTo("admin@example.com");
-    assertThat(info.username).isEqualTo("admin");
-    accountIndexedCounter.assertNoReindex();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      AccountInfo info = gApi.accounts().id("admin").get();
+      assertThat(info.name).isEqualTo("Administrator");
+      assertThat(info.email).isEqualTo("admin@example.com");
+      assertThat(info.username).isEqualTo("admin");
+      accountIndexedCounter.assertNoReindex();
+    }
   }
 
   @Test
   public void getByIntId() throws Exception {
-    AccountInfo info = gApi.accounts().id("admin").get();
-    AccountInfo infoByIntId = gApi.accounts().id(info._accountId).get();
-    assertThat(info.name).isEqualTo(infoByIntId.name);
-    accountIndexedCounter.assertNoReindex();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      AccountInfo info = gApi.accounts().id("admin").get();
+      AccountInfo infoByIntId = gApi.accounts().id(info._accountId).get();
+      assertThat(info.name).isEqualTo(infoByIntId.name);
+      accountIndexedCounter.assertNoReindex();
+    }
   }
 
   @Test
   public void self() throws Exception {
-    AccountInfo info = gApi.accounts().self().get();
-    assertUser(info, admin);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      AccountInfo info = gApi.accounts().self().get();
+      assertUser(info, admin);
 
-    info = gApi.accounts().id("self").get();
-    assertUser(info, admin);
-    accountIndexedCounter.assertNoReindex();
+      info = gApi.accounts().id("self").get();
+      assertUser(info, admin);
+      accountIndexedCounter.assertNoReindex();
+    }
   }
 
   @Test
   public void active() throws Exception {
-    int id = gApi.accounts().id("user").get()._accountId;
-    assertThat(gApi.accounts().id("user").getActive()).isTrue();
-    gApi.accounts().id("user").setActive(false);
-    accountIndexedCounter.assertReindexOf(user);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      int id = gApi.accounts().id("user").get()._accountId;
+      assertThat(gApi.accounts().id("user").getActive()).isTrue();
+      gApi.accounts().id("user").setActive(false);
+      accountIndexedCounter.assertReindexOf(user);
 
-    // Inactive users may only be resolved by ID.
-    ResourceNotFoundException thrown =
-        assertThrows(ResourceNotFoundException.class, () -> gApi.accounts().id("user"));
-    assertThat(thrown)
-        .hasMessageThat()
-        .isEqualTo(
-            "Account 'user' only matches inactive accounts. To use an inactive account, retry"
-                + " with one of the following exact account IDs:\n"
-                + id
-                + ": User <user@example.com>");
-    assertThat(gApi.accounts().id(id).getActive()).isFalse();
+      // Inactive users may only be resolved by ID.
+      ResourceNotFoundException thrown =
+          assertThrows(ResourceNotFoundException.class, () -> gApi.accounts().id("user"));
+      assertThat(thrown)
+          .hasMessageThat()
+          .isEqualTo(
+              "Account 'user' only matches inactive accounts. To use an inactive account, retry"
+                  + " with one of the following exact account IDs:\n"
+                  + id
+                  + ": User <user@example.com>");
+      assertThat(gApi.accounts().id(id).getActive()).isFalse();
 
-    gApi.accounts().id(id).setActive(true);
-    assertThat(gApi.accounts().id("user").getActive()).isTrue();
-    accountIndexedCounter.assertReindexOf(user);
+      gApi.accounts().id(id).setActive(true);
+      assertThat(gApi.accounts().id("user").getActive()).isTrue();
+      accountIndexedCounter.assertReindexOf(user);
+    }
   }
 
   @Test
   public void shouldAllowQueryByEmailForInactiveUser() throws Exception {
-    Account.Id activatableAccountId =
-        accountOperations.newAccount().inactive().preferredEmail("foo@activatable.com").create();
-    accountIndexedCounter.assertReindexOf(activatableAccountId, 1);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      Account.Id activatableAccountId =
+          accountOperations.newAccount().inactive().preferredEmail("foo@activatable.com").create();
+      accountIndexedCounter.assertReindexOf(activatableAccountId, 1);
+    }
 
     gApi.changes().query("owner:foo@activatable.com").get();
   }
 
   @Test
   public void shouldAllowQueryByUserNameForInactiveUser() throws Exception {
-    Account.Id activatableAccountId =
-        accountOperations.newAccount().inactive().username("foo").create();
-    accountIndexedCounter.assertReindexOf(activatableAccountId, 1);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      Account.Id activatableAccountId =
+          accountOperations.newAccount().inactive().username("foo").create();
+      accountIndexedCounter.assertReindexOf(activatableAccountId, 1);
+    }
 
     gApi.changes().query("owner:foo").get();
   }
@@ -688,84 +696,96 @@
 
   @Test
   public void starUnstarChange() throws Exception {
-    PushOneCommit.Result r = createChange();
-    String triplet = project.get() + "~master~" + r.getChangeId();
-    refUpdateCounter.clear();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    RefUpdateCounter refUpdateCounter = new RefUpdateCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter).add(refUpdateCounter)) {
+      PushOneCommit.Result r = createChange();
+      String triplet = project.get() + "~master~" + r.getChangeId();
+      refUpdateCounter.clear();
 
-    gApi.accounts().self().starChange(triplet);
-    ChangeInfo change = info(triplet);
-    assertThat(change.starred).isTrue();
-    assertThat(change.stars).contains(DEFAULT_LABEL);
-    refUpdateCounter.assertRefUpdateFor(
-        RefUpdateCounter.projectRef(
-            allUsers, RefNames.refsStarredChanges(Change.id(change._number), admin.id())));
+      gApi.accounts().self().starChange(triplet);
+      ChangeInfo change = info(triplet);
+      assertThat(change.starred).isTrue();
+      assertThat(change.stars).contains(DEFAULT_LABEL);
+      refUpdateCounter.assertRefUpdateFor(
+          RefUpdateCounter.projectRef(
+              allUsers, RefNames.refsStarredChanges(Change.id(change._number), admin.id())));
 
-    gApi.accounts().self().unstarChange(triplet);
-    change = info(triplet);
-    assertThat(change.starred).isNull();
-    assertThat(change.stars).isNull();
-    refUpdateCounter.assertRefUpdateFor(
-        RefUpdateCounter.projectRef(
-            allUsers, RefNames.refsStarredChanges(Change.id(change._number), admin.id())));
+      gApi.accounts().self().unstarChange(triplet);
+      change = info(triplet);
+      assertThat(change.starred).isNull();
+      assertThat(change.stars).isNull();
+      refUpdateCounter.assertRefUpdateFor(
+          RefUpdateCounter.projectRef(
+              allUsers, RefNames.refsStarredChanges(Change.id(change._number), admin.id())));
 
-    accountIndexedCounter.assertNoReindex();
+      accountIndexedCounter.assertNoReindex();
+    }
   }
 
   @Test
   public void starUnstarChangeWithLabels() throws Exception {
-    PushOneCommit.Result r = createChange();
-    String triplet = project.get() + "~master~" + r.getChangeId();
-    refUpdateCounter.clear();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    RefUpdateCounter refUpdateCounter = new RefUpdateCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter).add(refUpdateCounter)) {
+      PushOneCommit.Result r = createChange();
+      String triplet = project.get() + "~master~" + r.getChangeId();
+      refUpdateCounter.clear();
 
-    assertThat(gApi.accounts().self().getStars(triplet)).isEmpty();
-    assertThat(gApi.accounts().self().getStarredChanges()).isEmpty();
+      assertThat(gApi.accounts().self().getStars(triplet)).isEmpty();
+      assertThat(gApi.accounts().self().getStarredChanges()).isEmpty();
 
-    gApi.accounts()
-        .self()
-        .setStars(triplet, new StarsInput(ImmutableSet.of(DEFAULT_LABEL, "red", "blue")));
-    ChangeInfo change = info(triplet);
-    assertThat(change.starred).isTrue();
-    assertThat(change.stars).containsExactly("blue", "red", DEFAULT_LABEL).inOrder();
-    assertThat(gApi.accounts().self().getStars(triplet))
-        .containsExactly("blue", "red", DEFAULT_LABEL)
-        .inOrder();
-    List<ChangeInfo> starredChanges = gApi.accounts().self().getStarredChanges();
-    assertThat(starredChanges).hasSize(1);
-    ChangeInfo starredChange = starredChanges.get(0);
-    assertThat(starredChange._number).isEqualTo(r.getChange().getId().get());
-    assertThat(starredChange.starred).isTrue();
-    assertThat(starredChange.stars).containsExactly("blue", "red", DEFAULT_LABEL).inOrder();
-    refUpdateCounter.assertRefUpdateFor(
-        RefUpdateCounter.projectRef(
-            allUsers, RefNames.refsStarredChanges(Change.id(change._number), admin.id())));
+      gApi.accounts()
+          .self()
+          .setStars(triplet, new StarsInput(ImmutableSet.of(DEFAULT_LABEL, "red", "blue")));
+      ChangeInfo change = info(triplet);
+      assertThat(change.starred).isTrue();
+      assertThat(change.stars).containsExactly("blue", "red", DEFAULT_LABEL).inOrder();
+      assertThat(gApi.accounts().self().getStars(triplet))
+          .containsExactly("blue", "red", DEFAULT_LABEL)
+          .inOrder();
+      List<ChangeInfo> starredChanges = gApi.accounts().self().getStarredChanges();
+      assertThat(starredChanges).hasSize(1);
+      ChangeInfo starredChange = starredChanges.get(0);
+      assertThat(starredChange._number).isEqualTo(r.getChange().getId().get());
+      assertThat(starredChange.starred).isTrue();
+      assertThat(starredChange.stars).containsExactly("blue", "red", DEFAULT_LABEL).inOrder();
+      refUpdateCounter.assertRefUpdateFor(
+          RefUpdateCounter.projectRef(
+              allUsers, RefNames.refsStarredChanges(Change.id(change._number), admin.id())));
 
-    gApi.accounts()
-        .self()
-        .setStars(
-            triplet,
-            new StarsInput(ImmutableSet.of("yellow"), ImmutableSet.of(DEFAULT_LABEL, "blue")));
-    change = info(triplet);
-    assertThat(change.starred).isNull();
-    assertThat(change.stars).containsExactly("red", "yellow").inOrder();
-    assertThat(gApi.accounts().self().getStars(triplet)).containsExactly("red", "yellow").inOrder();
-    starredChanges = gApi.accounts().self().getStarredChanges();
-    assertThat(starredChanges).hasSize(1);
-    starredChange = starredChanges.get(0);
-    assertThat(starredChange._number).isEqualTo(r.getChange().getId().get());
-    assertThat(starredChange.starred).isNull();
-    assertThat(starredChange.stars).containsExactly("red", "yellow").inOrder();
-    refUpdateCounter.assertRefUpdateFor(
-        RefUpdateCounter.projectRef(
-            allUsers, RefNames.refsStarredChanges(Change.id(change._number), admin.id())));
+      gApi.accounts()
+          .self()
+          .setStars(
+              triplet,
+              new StarsInput(ImmutableSet.of("yellow"), ImmutableSet.of(DEFAULT_LABEL, "blue")));
+      change = info(triplet);
+      assertThat(change.starred).isNull();
+      assertThat(change.stars).containsExactly("red", "yellow").inOrder();
+      assertThat(gApi.accounts().self().getStars(triplet))
+          .containsExactly("red", "yellow")
+          .inOrder();
+      starredChanges = gApi.accounts().self().getStarredChanges();
+      assertThat(starredChanges).hasSize(1);
+      starredChange = starredChanges.get(0);
+      assertThat(starredChange._number).isEqualTo(r.getChange().getId().get());
+      assertThat(starredChange.starred).isNull();
+      assertThat(starredChange.stars).containsExactly("red", "yellow").inOrder();
+      refUpdateCounter.assertRefUpdateFor(
+          RefUpdateCounter.projectRef(
+              allUsers, RefNames.refsStarredChanges(Change.id(change._number), admin.id())));
 
-    accountIndexedCounter.assertNoReindex();
+      accountIndexedCounter.assertNoReindex();
 
-    requestScopeOperations.setApiUser(user.id());
-    AuthException thrown =
-        assertThrows(
-            AuthException.class,
-            () -> gApi.accounts().id(Integer.toString((admin.id().get()))).getStars(triplet));
-    assertThat(thrown).hasMessageThat().contains("not allowed to get stars of another account");
+      requestScopeOperations.setApiUser(user.id());
+      AuthException thrown =
+          assertThrows(
+              AuthException.class,
+              () -> gApi.accounts().id(Integer.toString((admin.id().get()))).getStars(triplet));
+      assertThat(thrown).hasMessageThat().contains("not allowed to get stars of another account");
+    }
   }
 
   @Test
@@ -825,65 +845,81 @@
 
   @Test
   public void ignoreChangeBySetStars() throws Exception {
-    TestAccount user2 = accountCreator.user2();
-    accountIndexedCounter.clear();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestAccount user2 = accountCreator.user2();
+      accountIndexedCounter.clear();
 
-    PushOneCommit.Result r = createChange();
+      PushOneCommit.Result r = createChange();
 
-    AddReviewerInput in = new AddReviewerInput();
-    in.reviewer = user.email();
-    gApi.changes().id(r.getChangeId()).addReviewer(in);
+      AddReviewerInput in = new AddReviewerInput();
+      in.reviewer = user.email();
+      gApi.changes().id(r.getChangeId()).addReviewer(in);
 
-    in = new AddReviewerInput();
-    in.reviewer = user2.email();
-    gApi.changes().id(r.getChangeId()).addReviewer(in);
+      in = new AddReviewerInput();
+      in.reviewer = user2.email();
+      gApi.changes().id(r.getChangeId()).addReviewer(in);
 
-    requestScopeOperations.setApiUser(user.id());
-    gApi.accounts().self().setStars(r.getChangeId(), new StarsInput(ImmutableSet.of(IGNORE_LABEL)));
+      requestScopeOperations.setApiUser(user.id());
+      gApi.accounts()
+          .self()
+          .setStars(r.getChangeId(), new StarsInput(ImmutableSet.of(IGNORE_LABEL)));
 
-    sender.clear();
-    requestScopeOperations.setApiUser(admin.id());
-    gApi.changes().id(r.getChangeId()).abandon();
-    List<Message> messages = sender.getMessages();
-    assertThat(messages).hasSize(1);
-    assertThat(messages.get(0).rcpt()).containsExactly(user2.getEmailAddress());
-    accountIndexedCounter.assertNoReindex();
+      sender.clear();
+      requestScopeOperations.setApiUser(admin.id());
+      gApi.changes().id(r.getChangeId()).abandon();
+      List<Message> messages = sender.getMessages();
+      assertThat(messages).hasSize(1);
+      assertThat(messages.get(0).rcpt()).containsExactly(user2.getEmailAddress());
+      accountIndexedCounter.assertNoReindex();
+    }
   }
 
   @Test
   public void addReviewerToIgnoredChange() throws Exception {
-    PushOneCommit.Result r = createChange();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      PushOneCommit.Result r = createChange();
 
-    requestScopeOperations.setApiUser(user.id());
-    gApi.accounts().self().setStars(r.getChangeId(), new StarsInput(ImmutableSet.of(IGNORE_LABEL)));
+      requestScopeOperations.setApiUser(user.id());
+      gApi.accounts()
+          .self()
+          .setStars(r.getChangeId(), new StarsInput(ImmutableSet.of(IGNORE_LABEL)));
 
-    sender.clear();
-    requestScopeOperations.setApiUser(admin.id());
+      sender.clear();
+      requestScopeOperations.setApiUser(admin.id());
 
-    AddReviewerInput in = new AddReviewerInput();
-    in.reviewer = user.email();
-    gApi.changes().id(r.getChangeId()).addReviewer(in);
-    List<Message> messages = sender.getMessages();
-    assertThat(messages).hasSize(1);
-    Message message = messages.get(0);
-    assertThat(message.rcpt()).containsExactly(user.getEmailAddress());
-    assertMailReplyTo(message, admin.email());
-    accountIndexedCounter.assertNoReindex();
+      AddReviewerInput in = new AddReviewerInput();
+      in.reviewer = user.email();
+      gApi.changes().id(r.getChangeId()).addReviewer(in);
+      List<Message> messages = sender.getMessages();
+      assertThat(messages).hasSize(1);
+      Message message = messages.get(0);
+      assertThat(message.rcpt()).containsExactly(user.getEmailAddress());
+      assertMailReplyTo(message, admin.email());
+      accountIndexedCounter.assertNoReindex();
+    }
   }
 
   @Test
   public void suggestAccounts() throws Exception {
-    String adminUsername = "admin";
-    List<AccountInfo> result = gApi.accounts().suggestAccounts().withQuery(adminUsername).get();
-    assertThat(result).hasSize(1);
-    assertThat(result.get(0).username).isEqualTo(adminUsername);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String adminUsername = "admin";
+      List<AccountInfo> result = gApi.accounts().suggestAccounts().withQuery(adminUsername).get();
+      assertThat(result).hasSize(1);
+      assertThat(result.get(0).username).isEqualTo(adminUsername);
 
-    List<AccountInfo> resultShortcutApi = gApi.accounts().suggestAccounts(adminUsername).get();
-    assertThat(resultShortcutApi).hasSize(result.size());
+      List<AccountInfo> resultShortcutApi = gApi.accounts().suggestAccounts(adminUsername).get();
+      assertThat(resultShortcutApi).hasSize(result.size());
 
-    List<AccountInfo> emptyResult = gApi.accounts().suggestAccounts("unknown").get();
-    assertThat(emptyResult).isEmpty();
-    accountIndexedCounter.assertNoReindex();
+      List<AccountInfo> emptyResult = gApi.accounts().suggestAccounts("unknown").get();
+      assertThat(emptyResult).isEmpty();
+      accountIndexedCounter.assertNoReindex();
+    }
   }
 
   @Test
@@ -983,17 +1019,21 @@
 
   @Test
   public void addEmail() throws Exception {
-    List<String> emails = ImmutableList.of("new.email@example.com", "new.email@example.systems");
-    Set<String> currentEmails = getEmails();
-    for (String email : emails) {
-      assertThat(currentEmails).doesNotContain(email);
-      EmailInput input = newEmailInput(email);
-      gApi.accounts().self().addEmail(input);
-      accountIndexedCounter.assertReindexOf(admin);
-    }
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      List<String> emails = ImmutableList.of("new.email@example.com", "new.email@example.systems");
+      Set<String> currentEmails = getEmails();
+      for (String email : emails) {
+        assertThat(currentEmails).doesNotContain(email);
+        EmailInput input = newEmailInput(email);
+        gApi.accounts().self().addEmail(input);
+        accountIndexedCounter.assertReindexOf(admin);
+      }
 
-    requestScopeOperations.resetCurrentApiUser();
-    assertThat(getEmails()).containsAtLeastElementsIn(emails);
+      requestScopeOperations.resetCurrentApiUser();
+      assertThat(getEmails()).containsAtLeastElementsIn(emails);
+    }
   }
 
   @Test
@@ -1011,13 +1051,17 @@
 
             // Non-supported TLD  (see tlds-alpha-by-domain.txt)
             "new.email@example.africa");
-    for (String email : emails) {
-      EmailInput input = newEmailInput(email);
-      BadRequestException thrown =
-          assertThrows(BadRequestException.class, () -> gApi.accounts().self().addEmail(input));
-      assertWithMessage(email).that(thrown).hasMessageThat().isEqualTo("invalid email address");
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      for (String email : emails) {
+        EmailInput input = newEmailInput(email);
+        BadRequestException thrown =
+            assertThrows(BadRequestException.class, () -> gApi.accounts().self().addEmail(input));
+        assertWithMessage(email).that(thrown).hasMessageThat().isEqualTo("invalid email address");
+      }
+      accountIndexedCounter.assertNoReindex();
     }
-    accountIndexedCounter.assertNoReindex();
   }
 
   @Test
@@ -1097,62 +1141,74 @@
 
   @Test
   public void addEmailAndSetPreferred() throws Exception {
-    String email = "foo.bar@example.com";
-    EmailInput input = new EmailInput();
-    input.email = email;
-    input.noConfirmation = true;
-    input.preferred = true;
-    gApi.accounts().self().addEmail(input);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String email = "foo.bar@example.com";
+      EmailInput input = new EmailInput();
+      input.email = email;
+      input.noConfirmation = true;
+      input.preferred = true;
+      gApi.accounts().self().addEmail(input);
 
-    // Account is reindexed twice; once on adding the new email,
-    // and then again on setting the email preferred.
-    accountIndexedCounter.assertReindexOf(admin, 2);
+      // Account is reindexed twice; once on adding the new email,
+      // and then again on setting the email preferred.
+      accountIndexedCounter.assertReindexOf(admin, 2);
 
-    String preferred = gApi.accounts().self().get().email;
-    assertThat(preferred).isEqualTo(email);
+      String preferred = gApi.accounts().self().get().email;
+      assertThat(preferred).isEqualTo(email);
+    }
   }
 
   @Test
   public void deleteEmail() throws Exception {
-    String email = "foo.bar@example.com";
-    EmailInput input = newEmailInput(email);
-    gApi.accounts().self().addEmail(input);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String email = "foo.bar@example.com";
+      EmailInput input = newEmailInput(email);
+      gApi.accounts().self().addEmail(input);
 
-    requestScopeOperations.resetCurrentApiUser();
-    assertThat(getEmails()).contains(email);
+      requestScopeOperations.resetCurrentApiUser();
+      assertThat(getEmails()).contains(email);
 
-    accountIndexedCounter.clear();
-    gApi.accounts().self().deleteEmail(input.email);
-    accountIndexedCounter.assertReindexOf(admin);
+      accountIndexedCounter.clear();
+      gApi.accounts().self().deleteEmail(input.email);
+      accountIndexedCounter.assertReindexOf(admin);
 
-    requestScopeOperations.resetCurrentApiUser();
-    assertThat(getEmails()).doesNotContain(email);
+      requestScopeOperations.resetCurrentApiUser();
+      assertThat(getEmails()).doesNotContain(email);
+    }
   }
 
   @Test
   public void deletePreferredEmail() throws Exception {
-    String previous = gApi.accounts().self().get().email;
-    String email = "foo.bar.baz@example.com";
-    EmailInput input = new EmailInput();
-    input.email = email;
-    input.noConfirmation = true;
-    input.preferred = true;
-    gApi.accounts().self().addEmail(input);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String previous = gApi.accounts().self().get().email;
+      String email = "foo.bar.baz@example.com";
+      EmailInput input = new EmailInput();
+      input.email = email;
+      input.noConfirmation = true;
+      input.preferred = true;
+      gApi.accounts().self().addEmail(input);
 
-    // Account is reindexed twice; once on adding the new email,
-    // and then again on setting the email preferred.
-    accountIndexedCounter.assertReindexOf(admin, 2);
+      // Account is reindexed twice; once on adding the new email,
+      // and then again on setting the email preferred.
+      accountIndexedCounter.assertReindexOf(admin, 2);
 
-    // The new preferred email is set
-    assertThat(gApi.accounts().self().get().email).isEqualTo(email);
+      // The new preferred email is set
+      assertThat(gApi.accounts().self().get().email).isEqualTo(email);
 
-    accountIndexedCounter.clear();
-    gApi.accounts().self().deleteEmail(input.email);
-    accountIndexedCounter.assertReindexOf(admin);
+      accountIndexedCounter.clear();
+      gApi.accounts().self().deleteEmail(input.email);
+      accountIndexedCounter.assertReindexOf(admin);
 
-    requestScopeOperations.resetCurrentApiUser();
-    assertThat(getEmails()).containsExactly(previous);
-    assertThat(gApi.accounts().self().get().email).isNull();
+      requestScopeOperations.resetCurrentApiUser();
+      assertThat(getEmails()).containsExactly(previous);
+      assertThat(gApi.accounts().self().get().email).isNull();
+    }
   }
 
   @Test
@@ -1178,64 +1234,77 @@
 
   @Test
   public void deleteEmailFromCustomExternalIdSchemes() throws Exception {
-    String email = "foo.bar@example.com";
-    String extId1 = "foo:bar";
-    String extId2 = "foo:baz";
-    accountsUpdateProvider
-        .get()
-        .update(
-            "Add External IDs",
-            admin.id(),
-            u ->
-                u.addExternalId(
-                        ExternalId.createWithEmail(ExternalId.Key.parse(extId1), admin.id(), email))
-                    .addExternalId(
-                        ExternalId.createWithEmail(
-                            ExternalId.Key.parse(extId2), admin.id(), email)));
-    accountIndexedCounter.assertReindexOf(admin);
-    assertThat(
-            gApi.accounts().self().getExternalIds().stream().map(e -> e.identity).collect(toSet()))
-        .containsAtLeast(extId1, extId2);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String email = "foo.bar@example.com";
+      String extId1 = "foo:bar";
+      String extId2 = "foo:baz";
+      accountsUpdateProvider
+          .get()
+          .update(
+              "Add External IDs",
+              admin.id(),
+              u ->
+                  u.addExternalId(
+                          ExternalId.createWithEmail(
+                              ExternalId.Key.parse(extId1), admin.id(), email))
+                      .addExternalId(
+                          ExternalId.createWithEmail(
+                              ExternalId.Key.parse(extId2), admin.id(), email)));
+      accountIndexedCounter.assertReindexOf(admin);
+      assertThat(
+              gApi.accounts().self().getExternalIds().stream()
+                  .map(e -> e.identity)
+                  .collect(toSet()))
+          .containsAtLeast(extId1, extId2);
 
-    requestScopeOperations.resetCurrentApiUser();
-    assertThat(getEmails()).contains(email);
+      requestScopeOperations.resetCurrentApiUser();
+      assertThat(getEmails()).contains(email);
 
-    gApi.accounts().self().deleteEmail(email);
-    accountIndexedCounter.assertReindexOf(admin);
+      gApi.accounts().self().deleteEmail(email);
+      accountIndexedCounter.assertReindexOf(admin);
 
-    requestScopeOperations.resetCurrentApiUser();
-    assertThat(getEmails()).doesNotContain(email);
-    assertThat(
-            gApi.accounts().self().getExternalIds().stream().map(e -> e.identity).collect(toSet()))
-        .containsNoneOf(extId1, extId2);
+      requestScopeOperations.resetCurrentApiUser();
+      assertThat(getEmails()).doesNotContain(email);
+      assertThat(
+              gApi.accounts().self().getExternalIds().stream()
+                  .map(e -> e.identity)
+                  .collect(toSet()))
+          .containsNoneOf(extId1, extId2);
+    }
   }
 
   @Test
   public void deleteEmailOfOtherUser() throws Exception {
-    String email = "foo.bar@example.com";
-    EmailInput input = new EmailInput();
-    input.email = email;
-    input.noConfirmation = true;
-    gApi.accounts().id(user.id().get()).addEmail(input);
-    accountIndexedCounter.assertReindexOf(user);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String email = "foo.bar@example.com";
+      EmailInput input = new EmailInput();
+      input.email = email;
+      input.noConfirmation = true;
+      gApi.accounts().id(user.id().get()).addEmail(input);
+      accountIndexedCounter.assertReindexOf(user);
 
-    requestScopeOperations.setApiUser(user.id());
-    assertThat(getEmails()).contains(email);
+      requestScopeOperations.setApiUser(user.id());
+      assertThat(getEmails()).contains(email);
 
-    // admin can delete email of user
-    requestScopeOperations.setApiUser(admin.id());
-    gApi.accounts().id(user.id().get()).deleteEmail(email);
-    accountIndexedCounter.assertReindexOf(user);
+      // admin can delete email of user
+      requestScopeOperations.setApiUser(admin.id());
+      gApi.accounts().id(user.id().get()).deleteEmail(email);
+      accountIndexedCounter.assertReindexOf(user);
 
-    requestScopeOperations.setApiUser(user.id());
-    assertThat(getEmails()).doesNotContain(email);
+      requestScopeOperations.setApiUser(user.id());
+      assertThat(getEmails()).doesNotContain(email);
 
-    // user cannot delete email of admin
-    AuthException thrown =
-        assertThrows(
-            AuthException.class,
-            () -> gApi.accounts().id(admin.id().get()).deleteEmail(admin.email()));
-    assertThat(thrown).hasMessageThat().contains("modify account not permitted");
+      // user cannot delete email of admin
+      AuthException thrown =
+          assertThrows(
+              AuthException.class,
+              () -> gApi.accounts().id(admin.id().get()).deleteEmail(admin.email()));
+      assertThat(thrown).hasMessageThat().contains("modify account not permitted");
+    }
   }
 
   @Test
@@ -1301,17 +1370,21 @@
   public void putStatus() throws Exception {
     List<String> statuses = ImmutableList.of("OOO", "Busy");
     AccountInfo info;
-    for (String status : statuses) {
-      gApi.accounts().self().setStatus(status);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      for (String status : statuses) {
+        gApi.accounts().self().setStatus(status);
+        info = gApi.accounts().self().get();
+        assertUser(info, admin, status);
+        accountIndexedCounter.assertReindexOf(admin);
+      }
+
+      gApi.accounts().self().setStatus(null);
       info = gApi.accounts().self().get();
-      assertUser(info, admin, status);
+      assertUser(info, admin);
       accountIndexedCounter.assertReindexOf(admin);
     }
-
-    gApi.accounts().self().setStatus(null);
-    info = gApi.accounts().self().get();
-    assertUser(info, admin);
-    accountIndexedCounter.assertReindexOf(admin);
   }
 
   @Test
@@ -1347,61 +1420,65 @@
 
   @Test
   public void fetchUserBranch() throws Exception {
-    requestScopeOperations.setApiUser(user.id());
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      requestScopeOperations.setApiUser(user.id());
 
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers, user);
-    String userRefName = RefNames.refsUsers(user.id());
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers, user);
+      String userRefName = RefNames.refsUsers(user.id());
 
-    // remove default READ permissions
-    try (ProjectConfigUpdate u = updateProject(allUsers)) {
-      u.getConfig()
-          .getAccessSection(RefNames.REFS_USERS + "${" + RefPattern.USERID_SHARDED + "}", true)
-          .remove(new Permission(Permission.READ));
-      u.save();
+      // remove default READ permissions
+      try (ProjectConfigUpdate u = updateProject(allUsers)) {
+        u.getConfig()
+            .getAccessSection(RefNames.REFS_USERS + "${" + RefPattern.USERID_SHARDED + "}", true)
+            .remove(new Permission(Permission.READ));
+        u.save();
+      }
+
+      // deny READ permission that is inherited from All-Projects
+      projectOperations
+          .project(allUsers)
+          .forUpdate()
+          .add(deny(Permission.READ).ref(RefNames.REFS + "*").group(ANONYMOUS_USERS))
+          .update();
+
+      // fetching user branch without READ permission fails
+      assertThrows(TransportException.class, () -> fetch(allUsersRepo, userRefName + ":userRef"));
+
+      // allow each user to read its own user branch
+      projectOperations
+          .project(allUsers)
+          .forUpdate()
+          .add(
+              allow(Permission.READ)
+                  .ref(RefNames.REFS_USERS + "${" + RefPattern.USERID_SHARDED + "}")
+                  .group(REGISTERED_USERS))
+          .update();
+
+      // fetch user branch using refs/users/YY/XXXXXXX
+      fetch(allUsersRepo, userRefName + ":userRef");
+      Ref userRef = allUsersRepo.getRepository().exactRef("userRef");
+      assertThat(userRef).isNotNull();
+
+      // fetch user branch using refs/users/self
+      fetch(allUsersRepo, RefNames.REFS_USERS_SELF + ":userSelfRef");
+      Ref userSelfRef = allUsersRepo.getRepository().getRefDatabase().exactRef("userSelfRef");
+      assertThat(userSelfRef).isNotNull();
+      assertThat(userSelfRef.getObjectId()).isEqualTo(userRef.getObjectId());
+
+      accountIndexedCounter.assertNoReindex();
+
+      // fetching user branch of another user fails
+      String otherUserRefName = RefNames.refsUsers(admin.id());
+      TransportException thrown =
+          assertThrows(
+              TransportException.class,
+              () -> fetch(allUsersRepo, otherUserRefName + ":otherUserRef"));
+      assertThat(thrown)
+          .hasMessageThat()
+          .contains("Remote does not have " + otherUserRefName + " available for fetch.");
     }
-
-    // deny READ permission that is inherited from All-Projects
-    projectOperations
-        .project(allUsers)
-        .forUpdate()
-        .add(deny(Permission.READ).ref(RefNames.REFS + "*").group(ANONYMOUS_USERS))
-        .update();
-
-    // fetching user branch without READ permission fails
-    assertThrows(TransportException.class, () -> fetch(allUsersRepo, userRefName + ":userRef"));
-
-    // allow each user to read its own user branch
-    projectOperations
-        .project(allUsers)
-        .forUpdate()
-        .add(
-            allow(Permission.READ)
-                .ref(RefNames.REFS_USERS + "${" + RefPattern.USERID_SHARDED + "}")
-                .group(REGISTERED_USERS))
-        .update();
-
-    // fetch user branch using refs/users/YY/XXXXXXX
-    fetch(allUsersRepo, userRefName + ":userRef");
-    Ref userRef = allUsersRepo.getRepository().exactRef("userRef");
-    assertThat(userRef).isNotNull();
-
-    // fetch user branch using refs/users/self
-    fetch(allUsersRepo, RefNames.REFS_USERS_SELF + ":userSelfRef");
-    Ref userSelfRef = allUsersRepo.getRepository().getRefDatabase().exactRef("userSelfRef");
-    assertThat(userSelfRef).isNotNull();
-    assertThat(userSelfRef.getObjectId()).isEqualTo(userRef.getObjectId());
-
-    accountIndexedCounter.assertNoReindex();
-
-    // fetching user branch of another user fails
-    String otherUserRefName = RefNames.refsUsers(admin.id());
-    TransportException thrown =
-        assertThrows(
-            TransportException.class,
-            () -> fetch(allUsersRepo, otherUserRefName + ":otherUserRef"));
-    assertThat(thrown)
-        .hasMessageThat()
-        .contains("Remote does not have " + otherUserRefName + " available for fetch.");
   }
 
   @Test
@@ -1419,535 +1496,599 @@
 
   @Test
   public void pushToUserBranch() throws Exception {
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, RefNames.refsUsers(admin.id()) + ":userRef");
-    allUsersRepo.reset("userRef");
-    PushOneCommit push = pushFactory.create(admin.newIdent(), allUsersRepo);
-    push.to(RefNames.refsUsers(admin.id())).assertOkStatus();
-    accountIndexedCounter.assertReindexOf(admin);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, RefNames.refsUsers(admin.id()) + ":userRef");
+      allUsersRepo.reset("userRef");
+      PushOneCommit push = pushFactory.create(admin.newIdent(), allUsersRepo);
+      push.to(RefNames.refsUsers(admin.id())).assertOkStatus();
+      accountIndexedCounter.assertReindexOf(admin);
 
-    push = pushFactory.create(admin.newIdent(), allUsersRepo);
-    push.to(RefNames.REFS_USERS_SELF).assertOkStatus();
-    accountIndexedCounter.assertReindexOf(admin);
+      push = pushFactory.create(admin.newIdent(), allUsersRepo);
+      push.to(RefNames.REFS_USERS_SELF).assertOkStatus();
+      accountIndexedCounter.assertReindexOf(admin);
+    }
   }
 
   @Test
   public void pushToUserBranchForReview() throws Exception {
-    String userRefName = RefNames.refsUsers(admin.id());
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, userRefName + ":userRef");
-    allUsersRepo.reset("userRef");
-    PushOneCommit push = pushFactory.create(admin.newIdent(), allUsersRepo);
-    PushOneCommit.Result r = push.to(MagicBranch.NEW_CHANGE + userRefName);
-    r.assertOkStatus();
-    accountIndexedCounter.assertNoReindex();
-    assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRefName);
-    gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
-    gApi.changes().id(r.getChangeId()).current().submit();
-    accountIndexedCounter.assertReindexOf(admin);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String userRefName = RefNames.refsUsers(admin.id());
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, userRefName + ":userRef");
+      allUsersRepo.reset("userRef");
+      PushOneCommit push = pushFactory.create(admin.newIdent(), allUsersRepo);
+      PushOneCommit.Result r = push.to(MagicBranch.NEW_CHANGE + userRefName);
+      r.assertOkStatus();
+      accountIndexedCounter.assertNoReindex();
+      assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRefName);
+      gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
+      gApi.changes().id(r.getChangeId()).current().submit();
+      accountIndexedCounter.assertReindexOf(admin);
 
-    push = pushFactory.create(admin.newIdent(), allUsersRepo);
-    r = push.to(MagicBranch.NEW_CHANGE + RefNames.REFS_USERS_SELF);
-    r.assertOkStatus();
-    accountIndexedCounter.assertNoReindex();
-    assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRefName);
-    gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
-    gApi.changes().id(r.getChangeId()).current().submit();
-    accountIndexedCounter.assertReindexOf(admin);
+      push = pushFactory.create(admin.newIdent(), allUsersRepo);
+      r = push.to(MagicBranch.NEW_CHANGE + RefNames.REFS_USERS_SELF);
+      r.assertOkStatus();
+      accountIndexedCounter.assertNoReindex();
+      assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRefName);
+      gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
+      gApi.changes().id(r.getChangeId()).current().submit();
+      accountIndexedCounter.assertReindexOf(admin);
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchForReviewAndSubmit() throws Exception {
-    String userRef = RefNames.refsUsers(admin.id());
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, userRef + ":userRef");
-    allUsersRepo.reset("userRef");
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String userRef = RefNames.refsUsers(admin.id());
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, userRef + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_STATUS, "out-of-office");
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_STATUS, "out-of-office");
 
-    PushOneCommit.Result r =
-        pushFactory
-            .create(
-                admin.newIdent(),
-                allUsersRepo,
-                "Update account config",
-                AccountProperties.ACCOUNT_CONFIG,
-                ac.toText())
-            .to(MagicBranch.NEW_CHANGE + userRef);
-    r.assertOkStatus();
-    accountIndexedCounter.assertNoReindex();
-    assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
+      PushOneCommit.Result r =
+          pushFactory
+              .create(
+                  admin.newIdent(),
+                  allUsersRepo,
+                  "Update account config",
+                  AccountProperties.ACCOUNT_CONFIG,
+                  ac.toText())
+              .to(MagicBranch.NEW_CHANGE + userRef);
+      r.assertOkStatus();
+      accountIndexedCounter.assertNoReindex();
+      assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
 
-    gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
-    gApi.changes().id(r.getChangeId()).current().submit();
-    accountIndexedCounter.assertReindexOf(admin);
+      gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
+      gApi.changes().id(r.getChangeId()).current().submit();
+      accountIndexedCounter.assertReindexOf(admin);
 
-    AccountInfo info = gApi.accounts().self().get();
-    assertThat(info.email).isEqualTo(admin.email());
-    assertThat(info.name).isEqualTo(admin.fullName());
-    assertThat(info.status).isEqualTo("out-of-office");
+      AccountInfo info = gApi.accounts().self().get();
+      assertThat(info.email).isEqualTo(admin.email());
+      assertThat(info.name).isEqualTo(admin.fullName());
+      assertThat(info.status).isEqualTo("out-of-office");
+    }
   }
 
   @Test
   public void pushAccountConfigWithPrefEmailThatDoesNotExistAsExtIdToUserBranchForReviewAndSubmit()
       throws Exception {
-    TestAccount foo = accountCreator.create(name("foo"), name("foo") + "@example.com", "Foo");
-    String userRef = RefNames.refsUsers(foo.id());
-    accountIndexedCounter.clear();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestAccount foo = accountCreator.create(name("foo"), name("foo") + "@example.com", "Foo");
+      String userRef = RefNames.refsUsers(foo.id());
+      accountIndexedCounter.clear();
 
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers, foo);
-    fetch(allUsersRepo, userRef + ":userRef");
-    allUsersRepo.reset("userRef");
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers, foo);
+      fetch(allUsersRepo, userRef + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    String email = "some.email@example.com";
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_PREFERRED_EMAIL, email);
+      String email = "some.email@example.com";
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_PREFERRED_EMAIL, email);
 
-    PushOneCommit.Result r =
-        pushFactory
-            .create(
-                foo.newIdent(),
-                allUsersRepo,
-                "Update account config",
-                AccountProperties.ACCOUNT_CONFIG,
-                ac.toText())
-            .to(MagicBranch.NEW_CHANGE + userRef);
-    r.assertOkStatus();
-    accountIndexedCounter.assertNoReindex();
-    assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
+      PushOneCommit.Result r =
+          pushFactory
+              .create(
+                  foo.newIdent(),
+                  allUsersRepo,
+                  "Update account config",
+                  AccountProperties.ACCOUNT_CONFIG,
+                  ac.toText())
+              .to(MagicBranch.NEW_CHANGE + userRef);
+      r.assertOkStatus();
+      accountIndexedCounter.assertNoReindex();
+      assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
 
-    requestScopeOperations.setApiUser(foo.id());
-    gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
-    gApi.changes().id(r.getChangeId()).current().submit();
+      requestScopeOperations.setApiUser(foo.id());
+      gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
+      gApi.changes().id(r.getChangeId()).current().submit();
 
-    accountIndexedCounter.assertReindexOf(foo);
+      accountIndexedCounter.assertReindexOf(foo);
 
-    AccountInfo info = gApi.accounts().self().get();
-    assertThat(info.email).isEqualTo(email);
-    assertThat(info.name).isEqualTo(foo.fullName());
+      AccountInfo info = gApi.accounts().self().get();
+      assertThat(info.email).isEqualTo(email);
+      assertThat(info.name).isEqualTo(foo.fullName());
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchForReviewIsRejectedOnSubmitIfConfigIsInvalid()
       throws Exception {
-    String userRef = RefNames.refsUsers(admin.id());
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, userRef + ":userRef");
-    allUsersRepo.reset("userRef");
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String userRef = RefNames.refsUsers(admin.id());
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, userRef + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    PushOneCommit.Result r =
-        pushFactory
-            .create(
-                admin.newIdent(),
-                allUsersRepo,
-                "Update account config",
-                AccountProperties.ACCOUNT_CONFIG,
-                "invalid config")
-            .to(MagicBranch.NEW_CHANGE + userRef);
-    r.assertOkStatus();
-    accountIndexedCounter.assertNoReindex();
-    assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
+      PushOneCommit.Result r =
+          pushFactory
+              .create(
+                  admin.newIdent(),
+                  allUsersRepo,
+                  "Update account config",
+                  AccountProperties.ACCOUNT_CONFIG,
+                  "invalid config")
+              .to(MagicBranch.NEW_CHANGE + userRef);
+      r.assertOkStatus();
+      accountIndexedCounter.assertNoReindex();
+      assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
 
-    gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
-    ResourceConflictException thrown =
-        assertThrows(
-            ResourceConflictException.class,
-            () -> gApi.changes().id(r.getChangeId()).current().submit());
-    assertThat(thrown)
-        .hasMessageThat()
-        .contains(
-            String.format(
-                "invalid account configuration: commit '%s' has an invalid '%s' file for account"
-                    + " '%s': Invalid config file %s in commit %s",
-                r.getCommit().name(),
-                AccountProperties.ACCOUNT_CONFIG,
-                admin.id(),
-                AccountProperties.ACCOUNT_CONFIG,
-                r.getCommit().name()));
+      gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
+      ResourceConflictException thrown =
+          assertThrows(
+              ResourceConflictException.class,
+              () -> gApi.changes().id(r.getChangeId()).current().submit());
+      assertThat(thrown)
+          .hasMessageThat()
+          .contains(
+              String.format(
+                  "invalid account configuration: commit '%s' has an invalid '%s' file for account"
+                      + " '%s': Invalid config file %s in commit %s",
+                  r.getCommit().name(),
+                  AccountProperties.ACCOUNT_CONFIG,
+                  admin.id(),
+                  AccountProperties.ACCOUNT_CONFIG,
+                  r.getCommit().name()));
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchForReviewIsRejectedOnSubmitIfPreferredEmailIsInvalid()
       throws Exception {
-    String userRef = RefNames.refsUsers(admin.id());
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, userRef + ":userRef");
-    allUsersRepo.reset("userRef");
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String userRef = RefNames.refsUsers(admin.id());
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, userRef + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    String noEmail = "no.email";
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_PREFERRED_EMAIL, noEmail);
+      String noEmail = "no.email";
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_PREFERRED_EMAIL, noEmail);
 
-    PushOneCommit.Result r =
-        pushFactory
-            .create(
-                admin.newIdent(),
-                allUsersRepo,
-                "Update account config",
-                AccountProperties.ACCOUNT_CONFIG,
-                ac.toText())
-            .to(MagicBranch.NEW_CHANGE + userRef);
-    r.assertOkStatus();
-    accountIndexedCounter.assertNoReindex();
-    assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
+      PushOneCommit.Result r =
+          pushFactory
+              .create(
+                  admin.newIdent(),
+                  allUsersRepo,
+                  "Update account config",
+                  AccountProperties.ACCOUNT_CONFIG,
+                  ac.toText())
+              .to(MagicBranch.NEW_CHANGE + userRef);
+      r.assertOkStatus();
+      accountIndexedCounter.assertNoReindex();
+      assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
 
-    gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
-    ResourceConflictException thrown =
-        assertThrows(
-            ResourceConflictException.class,
-            () -> gApi.changes().id(r.getChangeId()).current().submit());
-    assertThat(thrown)
-        .hasMessageThat()
-        .contains(
-            String.format(
-                "invalid account configuration: invalid preferred email '%s' for account '%s'",
-                noEmail, admin.id()));
+      gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
+      ResourceConflictException thrown =
+          assertThrows(
+              ResourceConflictException.class,
+              () -> gApi.changes().id(r.getChangeId()).current().submit());
+      assertThat(thrown)
+          .hasMessageThat()
+          .contains(
+              String.format(
+                  "invalid account configuration: invalid preferred email '%s' for account '%s'",
+                  noEmail, admin.id()));
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchForReviewIsRejectedOnSubmitIfOwnAccountIsDeactivated()
       throws Exception {
-    String userRef = RefNames.refsUsers(admin.id());
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, userRef + ":userRef");
-    allUsersRepo.reset("userRef");
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      String userRef = RefNames.refsUsers(admin.id());
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, userRef + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setBoolean(AccountProperties.ACCOUNT, null, AccountProperties.KEY_ACTIVE, false);
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setBoolean(AccountProperties.ACCOUNT, null, AccountProperties.KEY_ACTIVE, false);
 
-    PushOneCommit.Result r =
-        pushFactory
-            .create(
-                admin.newIdent(),
-                allUsersRepo,
-                "Update account config",
-                AccountProperties.ACCOUNT_CONFIG,
-                ac.toText())
-            .to(MagicBranch.NEW_CHANGE + userRef);
-    r.assertOkStatus();
-    accountIndexedCounter.assertNoReindex();
-    assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
+      PushOneCommit.Result r =
+          pushFactory
+              .create(
+                  admin.newIdent(),
+                  allUsersRepo,
+                  "Update account config",
+                  AccountProperties.ACCOUNT_CONFIG,
+                  ac.toText())
+              .to(MagicBranch.NEW_CHANGE + userRef);
+      r.assertOkStatus();
+      accountIndexedCounter.assertNoReindex();
+      assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
 
-    gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
-    ResourceConflictException thrown =
-        assertThrows(
-            ResourceConflictException.class,
-            () -> gApi.changes().id(r.getChangeId()).current().submit());
-    assertThat(thrown)
-        .hasMessageThat()
-        .contains("invalid account configuration: cannot deactivate own account");
+      gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
+      ResourceConflictException thrown =
+          assertThrows(
+              ResourceConflictException.class,
+              () -> gApi.changes().id(r.getChangeId()).current().submit());
+      assertThat(thrown)
+          .hasMessageThat()
+          .contains("invalid account configuration: cannot deactivate own account");
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchForReviewDeactivateOtherAccount() throws Exception {
-    projectOperations
-        .allProjectsForUpdate()
-        .add(allowCapability(GlobalCapability.ACCESS_DATABASE).group(REGISTERED_USERS))
-        .update();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      projectOperations
+          .allProjectsForUpdate()
+          .add(allowCapability(GlobalCapability.ACCESS_DATABASE).group(REGISTERED_USERS))
+          .update();
 
-    TestAccount foo = accountCreator.create(name("foo"));
-    assertThat(gApi.accounts().id(foo.id().get()).getActive()).isTrue();
-    String userRef = RefNames.refsUsers(foo.id());
-    accountIndexedCounter.clear();
+      TestAccount foo = accountCreator.create(name("foo"));
+      assertThat(gApi.accounts().id(foo.id().get()).getActive()).isTrue();
+      String userRef = RefNames.refsUsers(foo.id());
+      accountIndexedCounter.clear();
 
-    projectOperations
-        .project(allUsers)
-        .forUpdate()
-        .add(allow(Permission.PUSH).ref(userRef).group(adminGroupUuid()))
-        .add(allowLabel("Code-Review").ref(userRef).group(adminGroupUuid()).range(-2, 2))
-        .add(allow(Permission.SUBMIT).ref(userRef).group(adminGroupUuid()))
-        .update();
+      projectOperations
+          .project(allUsers)
+          .forUpdate()
+          .add(allow(Permission.PUSH).ref(userRef).group(adminGroupUuid()))
+          .add(allowLabel("Code-Review").ref(userRef).group(adminGroupUuid()).range(-2, 2))
+          .add(allow(Permission.SUBMIT).ref(userRef).group(adminGroupUuid()))
+          .update();
 
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, userRef + ":userRef");
-    allUsersRepo.reset("userRef");
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, userRef + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setBoolean(AccountProperties.ACCOUNT, null, AccountProperties.KEY_ACTIVE, false);
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setBoolean(AccountProperties.ACCOUNT, null, AccountProperties.KEY_ACTIVE, false);
 
-    PushOneCommit.Result r =
-        pushFactory
-            .create(
-                admin.newIdent(),
-                allUsersRepo,
-                "Update account config",
-                AccountProperties.ACCOUNT_CONFIG,
-                ac.toText())
-            .to(MagicBranch.NEW_CHANGE + userRef);
-    r.assertOkStatus();
-    accountIndexedCounter.assertNoReindex();
-    assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
+      PushOneCommit.Result r =
+          pushFactory
+              .create(
+                  admin.newIdent(),
+                  allUsersRepo,
+                  "Update account config",
+                  AccountProperties.ACCOUNT_CONFIG,
+                  ac.toText())
+              .to(MagicBranch.NEW_CHANGE + userRef);
+      r.assertOkStatus();
+      accountIndexedCounter.assertNoReindex();
+      assertThat(r.getChange().change().getDest().branch()).isEqualTo(userRef);
 
-    gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
-    gApi.changes().id(r.getChangeId()).current().submit();
-    accountIndexedCounter.assertReindexOf(foo);
+      gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
+      gApi.changes().id(r.getChangeId()).current().submit();
+      accountIndexedCounter.assertReindexOf(foo);
 
-    assertThat(gApi.accounts().id(foo.id().get()).getActive()).isFalse();
+      assertThat(gApi.accounts().id(foo.id().get()).getActive()).isFalse();
+    }
   }
 
   @Test
   public void pushWatchConfigToUserBranch() throws Exception {
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, RefNames.refsUsers(admin.id()) + ":userRef");
-    allUsersRepo.reset("userRef");
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, RefNames.refsUsers(admin.id()) + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    Config wc = new Config();
-    wc.setString(
-        ProjectWatches.PROJECT,
-        project.get(),
-        ProjectWatches.KEY_NOTIFY,
-        ProjectWatches.NotifyValue.create(null, EnumSet.of(NotifyType.ALL_COMMENTS)).toString());
-    PushOneCommit push =
-        pushFactory.create(
-            admin.newIdent(),
-            allUsersRepo,
-            "Add project watch",
-            ProjectWatches.WATCH_CONFIG,
-            wc.toText());
-    push.to(RefNames.REFS_USERS_SELF).assertOkStatus();
-    accountIndexedCounter.assertReindexOf(admin);
+      Config wc = new Config();
+      wc.setString(
+          ProjectWatches.PROJECT,
+          project.get(),
+          ProjectWatches.KEY_NOTIFY,
+          ProjectWatches.NotifyValue.create(null, EnumSet.of(NotifyType.ALL_COMMENTS)).toString());
+      PushOneCommit push =
+          pushFactory.create(
+              admin.newIdent(),
+              allUsersRepo,
+              "Add project watch",
+              ProjectWatches.WATCH_CONFIG,
+              wc.toText());
+      push.to(RefNames.REFS_USERS_SELF).assertOkStatus();
+      accountIndexedCounter.assertReindexOf(admin);
 
-    String invalidNotifyValue = "]invalid[";
-    wc.setString(
-        ProjectWatches.PROJECT, project.get(), ProjectWatches.KEY_NOTIFY, invalidNotifyValue);
-    push =
-        pushFactory.create(
-            admin.newIdent(),
-            allUsersRepo,
-            "Add invalid project watch",
-            ProjectWatches.WATCH_CONFIG,
-            wc.toText());
-    PushOneCommit.Result r = push.to(RefNames.REFS_USERS_SELF);
-    r.assertErrorStatus("invalid account configuration");
-    r.assertMessage(
-        String.format(
-            "%s: Invalid project watch of account %d for project %s: %s",
-            ProjectWatches.WATCH_CONFIG, admin.id().get(), project.get(), invalidNotifyValue));
+      String invalidNotifyValue = "]invalid[";
+      wc.setString(
+          ProjectWatches.PROJECT, project.get(), ProjectWatches.KEY_NOTIFY, invalidNotifyValue);
+      push =
+          pushFactory.create(
+              admin.newIdent(),
+              allUsersRepo,
+              "Add invalid project watch",
+              ProjectWatches.WATCH_CONFIG,
+              wc.toText());
+      PushOneCommit.Result r = push.to(RefNames.REFS_USERS_SELF);
+      r.assertErrorStatus("invalid account configuration");
+      r.assertMessage(
+          String.format(
+              "%s: Invalid project watch of account %d for project %s: %s",
+              ProjectWatches.WATCH_CONFIG, admin.id().get(), project.get(), invalidNotifyValue));
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranch() throws Exception {
-    TestAccount oooUser = accountCreator.create("away", "away@mail.invalid", "Ambrose Way");
-    requestScopeOperations.setApiUser(oooUser.id());
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestAccount oooUser = accountCreator.create("away", "away@mail.invalid", "Ambrose Way");
+      requestScopeOperations.setApiUser(oooUser.id());
 
-    // Must clone as oooUser to ensure the push is allowed.
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers, oooUser);
-    fetch(allUsersRepo, RefNames.refsUsers(oooUser.id()) + ":userRef");
-    allUsersRepo.reset("userRef");
+      // Must clone as oooUser to ensure the push is allowed.
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers, oooUser);
+      fetch(allUsersRepo, RefNames.refsUsers(oooUser.id()) + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_STATUS, "out-of-office");
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_STATUS, "out-of-office");
 
-    accountIndexedCounter.clear();
-    pushFactory
-        .create(
-            oooUser.newIdent(),
-            allUsersRepo,
-            "Update account config",
-            AccountProperties.ACCOUNT_CONFIG,
-            ac.toText())
-        .to(RefNames.refsUsers(oooUser.id()))
-        .assertOkStatus();
+      accountIndexedCounter.clear();
+      pushFactory
+          .create(
+              oooUser.newIdent(),
+              allUsersRepo,
+              "Update account config",
+              AccountProperties.ACCOUNT_CONFIG,
+              ac.toText())
+          .to(RefNames.refsUsers(oooUser.id()))
+          .assertOkStatus();
 
-    accountIndexedCounter.assertReindexOf(oooUser);
+      accountIndexedCounter.assertReindexOf(oooUser);
 
-    AccountInfo info = gApi.accounts().self().get();
-    assertThat(info.email).isEqualTo(oooUser.email());
-    assertThat(info.name).isEqualTo(oooUser.fullName());
-    assertThat(info.status).isEqualTo("out-of-office");
+      AccountInfo info = gApi.accounts().self().get();
+      assertThat(info.email).isEqualTo(oooUser.email());
+      assertThat(info.name).isEqualTo(oooUser.fullName());
+      assertThat(info.status).isEqualTo("out-of-office");
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchIsRejectedIfConfigIsInvalid() throws Exception {
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, RefNames.refsUsers(admin.id()) + ":userRef");
-    allUsersRepo.reset("userRef");
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, RefNames.refsUsers(admin.id()) + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    PushOneCommit.Result r =
-        pushFactory
-            .create(
-                admin.newIdent(),
-                allUsersRepo,
-                "Update account config",
-                AccountProperties.ACCOUNT_CONFIG,
-                "invalid config")
-            .to(RefNames.REFS_USERS_SELF);
-    r.assertErrorStatus("invalid account configuration");
-    r.assertMessage(
-        String.format(
-            "commit '%s' has an invalid '%s' file for account '%s':"
-                + " Invalid config file %s in commit %s",
-            r.getCommit().name(),
-            AccountProperties.ACCOUNT_CONFIG,
-            admin.id(),
-            AccountProperties.ACCOUNT_CONFIG,
-            r.getCommit().name()));
-    accountIndexedCounter.assertNoReindex();
+      PushOneCommit.Result r =
+          pushFactory
+              .create(
+                  admin.newIdent(),
+                  allUsersRepo,
+                  "Update account config",
+                  AccountProperties.ACCOUNT_CONFIG,
+                  "invalid config")
+              .to(RefNames.REFS_USERS_SELF);
+      r.assertErrorStatus("invalid account configuration");
+      r.assertMessage(
+          String.format(
+              "commit '%s' has an invalid '%s' file for account '%s':"
+                  + " Invalid config file %s in commit %s",
+              r.getCommit().name(),
+              AccountProperties.ACCOUNT_CONFIG,
+              admin.id(),
+              AccountProperties.ACCOUNT_CONFIG,
+              r.getCommit().name()));
+      accountIndexedCounter.assertNoReindex();
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchIsRejectedIfPreferredEmailIsInvalid() throws Exception {
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, RefNames.refsUsers(admin.id()) + ":userRef");
-    allUsersRepo.reset("userRef");
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, RefNames.refsUsers(admin.id()) + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    String noEmail = "no.email";
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_PREFERRED_EMAIL, noEmail);
+      String noEmail = "no.email";
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_PREFERRED_EMAIL, noEmail);
 
-    PushOneCommit.Result r =
-        pushFactory
-            .create(
-                admin.newIdent(),
-                allUsersRepo,
-                "Update account config",
-                AccountProperties.ACCOUNT_CONFIG,
-                ac.toText())
-            .to(RefNames.REFS_USERS_SELF);
-    r.assertErrorStatus("invalid account configuration");
-    r.assertMessage(
-        String.format("invalid preferred email '%s' for account '%s'", noEmail, admin.id()));
-    accountIndexedCounter.assertNoReindex();
+      PushOneCommit.Result r =
+          pushFactory
+              .create(
+                  admin.newIdent(),
+                  allUsersRepo,
+                  "Update account config",
+                  AccountProperties.ACCOUNT_CONFIG,
+                  ac.toText())
+              .to(RefNames.REFS_USERS_SELF);
+      r.assertErrorStatus("invalid account configuration");
+      r.assertMessage(
+          String.format("invalid preferred email '%s' for account '%s'", noEmail, admin.id()));
+      accountIndexedCounter.assertNoReindex();
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchInvalidPreferredEmailButNotChanged() throws Exception {
-    TestAccount foo = accountCreator.create(name("foo"), name("foo") + "@example.com", "Foo");
-    String userRef = RefNames.refsUsers(foo.id());
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestAccount foo = accountCreator.create(name("foo"), name("foo") + "@example.com", "Foo");
+      String userRef = RefNames.refsUsers(foo.id());
 
-    String noEmail = "no.email";
-    accountsUpdateProvider
-        .get()
-        .update("Set Preferred Email", foo.id(), u -> u.setPreferredEmail(noEmail));
-    accountIndexedCounter.clear();
+      String noEmail = "no.email";
+      accountsUpdateProvider
+          .get()
+          .update("Set Preferred Email", foo.id(), u -> u.setPreferredEmail(noEmail));
+      accountIndexedCounter.clear();
 
-    projectOperations
-        .project(allUsers)
-        .forUpdate()
-        .add(allow(Permission.PUSH).ref(userRef).group(REGISTERED_USERS))
-        .update();
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers, foo);
-    fetch(allUsersRepo, userRef + ":userRef");
-    allUsersRepo.reset("userRef");
+      projectOperations
+          .project(allUsers)
+          .forUpdate()
+          .add(allow(Permission.PUSH).ref(userRef).group(REGISTERED_USERS))
+          .update();
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers, foo);
+      fetch(allUsersRepo, userRef + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    String status = "in vacation";
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_STATUS, status);
+      String status = "in vacation";
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_STATUS, status);
 
-    pushFactory
-        .create(
-            foo.newIdent(),
-            allUsersRepo,
-            "Update account config",
-            AccountProperties.ACCOUNT_CONFIG,
-            ac.toText())
-        .to(userRef)
-        .assertOkStatus();
-    accountIndexedCounter.assertReindexOf(foo);
+      pushFactory
+          .create(
+              foo.newIdent(),
+              allUsersRepo,
+              "Update account config",
+              AccountProperties.ACCOUNT_CONFIG,
+              ac.toText())
+          .to(userRef)
+          .assertOkStatus();
+      accountIndexedCounter.assertReindexOf(foo);
 
-    AccountInfo info = gApi.accounts().id(foo.id().get()).get();
-    assertThat(info.email).isEqualTo(noEmail);
-    assertThat(info.name).isEqualTo(foo.fullName());
-    assertThat(info.status).isEqualTo(status);
+      AccountInfo info = gApi.accounts().id(foo.id().get()).get();
+      assertThat(info.email).isEqualTo(noEmail);
+      assertThat(info.name).isEqualTo(foo.fullName());
+      assertThat(info.status).isEqualTo(status);
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchIfPreferredEmailDoesNotExistAsExtId() throws Exception {
-    TestAccount foo = accountCreator.create(name("foo"), name("foo") + "@example.com", "Foo");
-    String userRef = RefNames.refsUsers(foo.id());
-    accountIndexedCounter.clear();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestAccount foo = accountCreator.create(name("foo"), name("foo") + "@example.com", "Foo");
+      String userRef = RefNames.refsUsers(foo.id());
+      accountIndexedCounter.clear();
 
-    projectOperations
-        .project(allUsers)
-        .forUpdate()
-        .add(allow(Permission.PUSH).ref(userRef).group(adminGroupUuid()))
-        .update();
+      projectOperations
+          .project(allUsers)
+          .forUpdate()
+          .add(allow(Permission.PUSH).ref(userRef).group(adminGroupUuid()))
+          .update();
 
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers, foo);
-    fetch(allUsersRepo, userRef + ":userRef");
-    allUsersRepo.reset("userRef");
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers, foo);
+      fetch(allUsersRepo, userRef + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    String email = "some.email@example.com";
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_PREFERRED_EMAIL, email);
+      String email = "some.email@example.com";
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setString(AccountProperties.ACCOUNT, null, AccountProperties.KEY_PREFERRED_EMAIL, email);
 
-    pushFactory
-        .create(
-            foo.newIdent(),
-            allUsersRepo,
-            "Update account config",
-            AccountProperties.ACCOUNT_CONFIG,
-            ac.toText())
-        .to(userRef)
-        .assertOkStatus();
-    accountIndexedCounter.assertReindexOf(foo);
+      pushFactory
+          .create(
+              foo.newIdent(),
+              allUsersRepo,
+              "Update account config",
+              AccountProperties.ACCOUNT_CONFIG,
+              ac.toText())
+          .to(userRef)
+          .assertOkStatus();
+      accountIndexedCounter.assertReindexOf(foo);
 
-    AccountInfo info = gApi.accounts().id(foo.id().get()).get();
-    assertThat(info.email).isEqualTo(email);
-    assertThat(info.name).isEqualTo(foo.fullName());
+      AccountInfo info = gApi.accounts().id(foo.id().get()).get();
+      assertThat(info.email).isEqualTo(email);
+      assertThat(info.name).isEqualTo(foo.fullName());
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchIsRejectedIfOwnAccountIsDeactivated() throws Exception {
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, RefNames.refsUsers(admin.id()) + ":userRef");
-    allUsersRepo.reset("userRef");
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, RefNames.refsUsers(admin.id()) + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setBoolean(AccountProperties.ACCOUNT, null, AccountProperties.KEY_ACTIVE, false);
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setBoolean(AccountProperties.ACCOUNT, null, AccountProperties.KEY_ACTIVE, false);
 
-    PushOneCommit.Result r =
-        pushFactory
-            .create(
-                admin.newIdent(),
-                allUsersRepo,
-                "Update account config",
-                AccountProperties.ACCOUNT_CONFIG,
-                ac.toText())
-            .to(RefNames.REFS_USERS_SELF);
-    r.assertErrorStatus("invalid account configuration");
-    r.assertMessage("cannot deactivate own account");
-    accountIndexedCounter.assertNoReindex();
+      PushOneCommit.Result r =
+          pushFactory
+              .create(
+                  admin.newIdent(),
+                  allUsersRepo,
+                  "Update account config",
+                  AccountProperties.ACCOUNT_CONFIG,
+                  ac.toText())
+              .to(RefNames.REFS_USERS_SELF);
+      r.assertErrorStatus("invalid account configuration");
+      r.assertMessage("cannot deactivate own account");
+      accountIndexedCounter.assertNoReindex();
+    }
   }
 
   @Test
   public void pushAccountConfigToUserBranchDeactivateOtherAccount() throws Exception {
-    projectOperations
-        .allProjectsForUpdate()
-        .add(allowCapability(GlobalCapability.ACCESS_DATABASE).group(REGISTERED_USERS))
-        .update();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      projectOperations
+          .allProjectsForUpdate()
+          .add(allowCapability(GlobalCapability.ACCESS_DATABASE).group(REGISTERED_USERS))
+          .update();
 
-    TestAccount foo = accountCreator.create(name("foo"));
-    assertThat(gApi.accounts().id(foo.id().get()).getActive()).isTrue();
-    String userRef = RefNames.refsUsers(foo.id());
-    accountIndexedCounter.clear();
+      TestAccount foo = accountCreator.create(name("foo"));
+      assertThat(gApi.accounts().id(foo.id().get()).getActive()).isTrue();
+      String userRef = RefNames.refsUsers(foo.id());
+      accountIndexedCounter.clear();
 
-    projectOperations
-        .project(allUsers)
-        .forUpdate()
-        .add(allow(Permission.PUSH).ref(userRef).group(adminGroupUuid()))
-        .update();
+      projectOperations
+          .project(allUsers)
+          .forUpdate()
+          .add(allow(Permission.PUSH).ref(userRef).group(adminGroupUuid()))
+          .update();
 
-    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
-    fetch(allUsersRepo, userRef + ":userRef");
-    allUsersRepo.reset("userRef");
+      TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+      fetch(allUsersRepo, userRef + ":userRef");
+      allUsersRepo.reset("userRef");
 
-    Config ac = getAccountConfig(allUsersRepo);
-    ac.setBoolean(AccountProperties.ACCOUNT, null, AccountProperties.KEY_ACTIVE, false);
+      Config ac = getAccountConfig(allUsersRepo);
+      ac.setBoolean(AccountProperties.ACCOUNT, null, AccountProperties.KEY_ACTIVE, false);
 
-    pushFactory
-        .create(
-            admin.newIdent(),
-            allUsersRepo,
-            "Update account config",
-            AccountProperties.ACCOUNT_CONFIG,
-            ac.toText())
-        .to(userRef)
-        .assertOkStatus();
-    accountIndexedCounter.assertReindexOf(foo);
+      pushFactory
+          .create(
+              admin.newIdent(),
+              allUsersRepo,
+              "Update account config",
+              AccountProperties.ACCOUNT_CONFIG,
+              ac.toText())
+          .to(userRef)
+          .assertOkStatus();
+      accountIndexedCounter.assertReindexOf(foo);
 
-    assertThat(gApi.accounts().id(foo.id().get()).getActive()).isFalse();
+      assertThat(gApi.accounts().id(foo.id().get()).getActive()).isFalse();
+    }
   }
 
   @Test
@@ -2150,103 +2291,127 @@
 
   @Test
   public void addOtherUsersGpgKey_Conflict() throws Exception {
-    // Both users have a matching external ID for this key.
-    addExternalIdEmail(admin, "test5@example.com");
-    accountsUpdateProvider
-        .get()
-        .update(
-            "Add External ID",
-            user.id(),
-            u -> u.addExternalId(ExternalId.create("foo", "myId", user.id())));
-    accountIndexedCounter.assertReindexOf(user);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      // Both users have a matching external ID for this key.
+      addExternalIdEmail(admin, "test5@example.com");
+      accountIndexedCounter.clear();
+      accountsUpdateProvider
+          .get()
+          .update(
+              "Add External ID",
+              user.id(),
+              u -> u.addExternalId(ExternalId.create("foo", "myId", user.id())));
+      accountIndexedCounter.assertReindexOf(user);
 
-    TestKey key = validKeyWithSecondUserId();
-    addGpgKey(key.getPublicKeyArmored());
-    requestScopeOperations.setApiUser(user.id());
+      TestKey key = validKeyWithSecondUserId();
+      addGpgKey(key.getPublicKeyArmored());
+      requestScopeOperations.setApiUser(user.id());
 
-    ResourceConflictException thrown =
-        assertThrows(
-            ResourceConflictException.class, () -> addGpgKey(user, key.getPublicKeyArmored()));
-    assertThat(thrown).hasMessageThat().contains("GPG key already associated with another account");
+      ResourceConflictException thrown =
+          assertThrows(
+              ResourceConflictException.class, () -> addGpgKey(user, key.getPublicKeyArmored()));
+      assertThat(thrown)
+          .hasMessageThat()
+          .contains("GPG key already associated with another account");
+    }
   }
 
   @Test
   public void listGpgKeys() throws Exception {
-    List<TestKey> keys = allValidKeys();
-    List<String> toAdd = new ArrayList<>(keys.size());
-    for (TestKey key : keys) {
-      addExternalIdEmail(admin, PushCertificateIdent.parse(key.getFirstUserId()).getEmailAddress());
-      toAdd.add(key.getPublicKeyArmored());
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      List<TestKey> keys = allValidKeys();
+      List<String> toAdd = new ArrayList<>(keys.size());
+      for (TestKey key : keys) {
+        addExternalIdEmail(
+            admin, PushCertificateIdent.parse(key.getFirstUserId()).getEmailAddress());
+        toAdd.add(key.getPublicKeyArmored());
+      }
+      accountIndexedCounter.clear();
+      gApi.accounts().self().putGpgKeys(toAdd, ImmutableList.of());
+      assertKeys(keys);
+      accountIndexedCounter.assertReindexOf(admin);
     }
-    gApi.accounts().self().putGpgKeys(toAdd, ImmutableList.of());
-    assertKeys(keys);
-    accountIndexedCounter.assertReindexOf(admin);
   }
 
   @Test
   public void deleteGpgKey() throws Exception {
-    TestKey key = validKeyWithoutExpiration();
-    String id = key.getKeyIdString();
-    addExternalIdEmail(admin, "test1@example.com");
-    addGpgKey(key.getPublicKeyArmored());
-    assertKeys(key);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      TestKey key = validKeyWithoutExpiration();
+      String id = key.getKeyIdString();
+      addExternalIdEmail(admin, "test1@example.com");
+      addGpgKey(key.getPublicKeyArmored());
+      assertKeys(key);
+      accountIndexedCounter.clear();
 
-    sender.clear();
-    gApi.accounts().self().gpgKey(id).delete();
-    accountIndexedCounter.assertReindexOf(admin);
-    assertKeys();
-    assertThat(sender.getMessages()).hasSize(1);
-    assertThat(sender.getMessages().get(0).body()).contains("GPG keys have been deleted");
+      sender.clear();
+      gApi.accounts().self().gpgKey(id).delete();
+      accountIndexedCounter.assertReindexOf(admin);
+      assertKeys();
+      assertThat(sender.getMessages()).hasSize(1);
+      assertThat(sender.getMessages().get(0).body()).contains("GPG keys have been deleted");
 
-    ResourceNotFoundException thrown =
-        assertThrows(
-            ResourceNotFoundException.class, () -> gApi.accounts().self().gpgKey(id).get());
-    assertThat(thrown).hasMessageThat().contains(id);
+      ResourceNotFoundException thrown =
+          assertThrows(
+              ResourceNotFoundException.class, () -> gApi.accounts().self().gpgKey(id).get());
+      assertThat(thrown).hasMessageThat().contains(id);
+    }
   }
 
   @Test
   public void addAndRemoveGpgKeys() throws Exception {
-    for (TestKey key : allValidKeys()) {
-      addExternalIdEmail(admin, PushCertificateIdent.parse(key.getFirstUserId()).getEmailAddress());
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      for (TestKey key : allValidKeys()) {
+        addExternalIdEmail(
+            admin, PushCertificateIdent.parse(key.getFirstUserId()).getEmailAddress());
+      }
+      accountIndexedCounter.clear();
+      TestKey key1 = validKeyWithoutExpiration();
+      TestKey key2 = validKeyWithExpiration();
+      TestKey key5 = validKeyWithSecondUserId();
+
+      Map<String, GpgKeyInfo> infos =
+          gApi.accounts()
+              .self()
+              .putGpgKeys(
+                  ImmutableList.of(key1.getPublicKeyArmored(), key2.getPublicKeyArmored()),
+                  ImmutableList.of(key5.getKeyIdString()));
+      assertThat(infos.keySet()).containsExactly(key1.getKeyIdString(), key2.getKeyIdString());
+      assertKeys(key1, key2);
+      accountIndexedCounter.assertReindexOf(admin);
+
+      infos =
+          gApi.accounts()
+              .self()
+              .putGpgKeys(
+                  ImmutableList.of(key5.getPublicKeyArmored()),
+                  ImmutableList.of(key1.getKeyIdString()));
+      assertThat(infos.keySet()).containsExactly(key1.getKeyIdString(), key5.getKeyIdString());
+      assertKeyMapContains(key5, infos);
+      assertThat(infos.get(key1.getKeyIdString()).key).isNull();
+      assertKeys(key2, key5);
+      accountIndexedCounter.assertReindexOf(admin);
+
+      BadRequestException thrown =
+          assertThrows(
+              BadRequestException.class,
+              () ->
+                  gApi.accounts()
+                      .self()
+                      .putGpgKeys(
+                          ImmutableList.of(key2.getPublicKeyArmored()),
+                          ImmutableList.of(key2.getKeyIdString())));
+      assertThat(thrown)
+          .hasMessageThat()
+          .contains("Cannot both add and delete key: " + keyToString(key2.getPublicKey()));
     }
-    TestKey key1 = validKeyWithoutExpiration();
-    TestKey key2 = validKeyWithExpiration();
-    TestKey key5 = validKeyWithSecondUserId();
-
-    Map<String, GpgKeyInfo> infos =
-        gApi.accounts()
-            .self()
-            .putGpgKeys(
-                ImmutableList.of(key1.getPublicKeyArmored(), key2.getPublicKeyArmored()),
-                ImmutableList.of(key5.getKeyIdString()));
-    assertThat(infos.keySet()).containsExactly(key1.getKeyIdString(), key2.getKeyIdString());
-    assertKeys(key1, key2);
-    accountIndexedCounter.assertReindexOf(admin);
-
-    infos =
-        gApi.accounts()
-            .self()
-            .putGpgKeys(
-                ImmutableList.of(key5.getPublicKeyArmored()),
-                ImmutableList.of(key1.getKeyIdString()));
-    assertThat(infos.keySet()).containsExactly(key1.getKeyIdString(), key5.getKeyIdString());
-    assertKeyMapContains(key5, infos);
-    assertThat(infos.get(key1.getKeyIdString()).key).isNull();
-    assertKeys(key2, key5);
-    accountIndexedCounter.assertReindexOf(admin);
-
-    BadRequestException thrown =
-        assertThrows(
-            BadRequestException.class,
-            () ->
-                gApi.accounts()
-                    .self()
-                    .putGpgKeys(
-                        ImmutableList.of(key2.getPublicKeyArmored()),
-                        ImmutableList.of(key2.getKeyIdString())));
-    assertThat(thrown)
-        .hasMessageThat()
-        .contains("Cannot both add and delete key: " + keyToString(key2.getPublicKey()));
   }
 
   @Test
@@ -2259,110 +2424,118 @@
   @Test
   @UseSsh
   public void sshKeys() throws Exception {
-    // The test account should initially have exactly one ssh key
-    List<SshKeyInfo> info = gApi.accounts().self().listSshKeys();
-    assertThat(info).hasSize(1);
-    assertSequenceNumbers(info);
-    SshKeyInfo key = info.get(0);
-    KeyPair keyPair = sshKeys.getKeyPair(admin);
-    String initial = TestSshKeys.publicKey(keyPair, admin.email());
-    assertThat(key.sshPublicKey).isEqualTo(initial);
-    accountIndexedCounter.assertNoReindex();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      // The test account should initially have exactly one ssh key
+      List<SshKeyInfo> info = gApi.accounts().self().listSshKeys();
+      assertThat(info).hasSize(1);
+      assertSequenceNumbers(info);
+      SshKeyInfo key = info.get(0);
+      KeyPair keyPair = sshKeys.getKeyPair(admin);
+      String initial = TestSshKeys.publicKey(keyPair, admin.email());
+      assertThat(key.sshPublicKey).isEqualTo(initial);
+      accountIndexedCounter.assertNoReindex();
 
-    // Add a new key
-    sender.clear();
-    String newKey = TestSshKeys.publicKey(TestSshKeys.genSshKey(), admin.email());
-    gApi.accounts().self().addSshKey(newKey);
-    info = gApi.accounts().self().listSshKeys();
-    assertThat(info).hasSize(2);
-    assertSequenceNumbers(info);
-    accountIndexedCounter.assertReindexOf(admin);
-    assertThat(sender.getMessages()).hasSize(1);
-    assertThat(sender.getMessages().get(0).body()).contains("new SSH keys have been added");
+      // Add a new key
+      sender.clear();
+      String newKey = TestSshKeys.publicKey(TestSshKeys.genSshKey(), admin.email());
+      gApi.accounts().self().addSshKey(newKey);
+      info = gApi.accounts().self().listSshKeys();
+      assertThat(info).hasSize(2);
+      assertSequenceNumbers(info);
+      accountIndexedCounter.assertReindexOf(admin);
+      assertThat(sender.getMessages()).hasSize(1);
+      assertThat(sender.getMessages().get(0).body()).contains("new SSH keys have been added");
 
-    // Add an existing key (the request succeeds, but the key isn't added again)
-    sender.clear();
-    gApi.accounts().self().addSshKey(initial);
-    info = gApi.accounts().self().listSshKeys();
-    assertThat(info).hasSize(2);
-    assertSequenceNumbers(info);
-    accountIndexedCounter.assertNoReindex();
-    // TODO: Issue 10769: Adding an already existing key should not result in a notification email
-    assertThat(sender.getMessages()).hasSize(1);
-    assertThat(sender.getMessages().get(0).body()).contains("new SSH keys have been added");
+      // Add an existing key (the request succeeds, but the key isn't added again)
+      sender.clear();
+      gApi.accounts().self().addSshKey(initial);
+      info = gApi.accounts().self().listSshKeys();
+      assertThat(info).hasSize(2);
+      assertSequenceNumbers(info);
+      accountIndexedCounter.assertNoReindex();
+      // TODO: Issue 10769: Adding an already existing key should not result in a notification email
+      assertThat(sender.getMessages()).hasSize(1);
+      assertThat(sender.getMessages().get(0).body()).contains("new SSH keys have been added");
 
-    // Add another new key
-    sender.clear();
-    String newKey2 = TestSshKeys.publicKey(TestSshKeys.genSshKey(), admin.email());
-    gApi.accounts().self().addSshKey(newKey2);
-    info = gApi.accounts().self().listSshKeys();
-    assertThat(info).hasSize(3);
-    assertSequenceNumbers(info);
-    accountIndexedCounter.assertReindexOf(admin);
-    assertThat(sender.getMessages()).hasSize(1);
-    assertThat(sender.getMessages().get(0).body()).contains("new SSH keys have been added");
+      // Add another new key
+      sender.clear();
+      String newKey2 = TestSshKeys.publicKey(TestSshKeys.genSshKey(), admin.email());
+      gApi.accounts().self().addSshKey(newKey2);
+      info = gApi.accounts().self().listSshKeys();
+      assertThat(info).hasSize(3);
+      assertSequenceNumbers(info);
+      accountIndexedCounter.assertReindexOf(admin);
+      assertThat(sender.getMessages()).hasSize(1);
+      assertThat(sender.getMessages().get(0).body()).contains("new SSH keys have been added");
 
-    // Delete second key
-    sender.clear();
-    gApi.accounts().self().deleteSshKey(2);
-    info = gApi.accounts().self().listSshKeys();
-    assertThat(info).hasSize(2);
-    assertThat(info.get(0).seq).isEqualTo(1);
-    assertThat(info.get(1).seq).isEqualTo(3);
-    accountIndexedCounter.assertReindexOf(admin);
+      // Delete second key
+      sender.clear();
+      gApi.accounts().self().deleteSshKey(2);
+      info = gApi.accounts().self().listSshKeys();
+      assertThat(info).hasSize(2);
+      assertThat(info.get(0).seq).isEqualTo(1);
+      assertThat(info.get(1).seq).isEqualTo(3);
+      accountIndexedCounter.assertReindexOf(admin);
 
-    assertThat(sender.getMessages()).hasSize(1);
-    assertThat(sender.getMessages().get(0).body()).contains("SSH keys have been deleted");
+      assertThat(sender.getMessages()).hasSize(1);
+      assertThat(sender.getMessages().get(0).body()).contains("SSH keys have been deleted");
 
-    // Mark first key as invalid
-    assertThat(info.get(0).valid).isTrue();
-    authorizedKeys.markKeyInvalid(admin.id(), 1);
-    info = gApi.accounts().self().listSshKeys();
-    assertThat(info).hasSize(2);
-    assertThat(info.get(0).seq).isEqualTo(1);
-    assertThat(info.get(0).valid).isFalse();
-    assertThat(info.get(1).seq).isEqualTo(3);
-    accountIndexedCounter.assertReindexOf(admin);
+      // Mark first key as invalid
+      assertThat(info.get(0).valid).isTrue();
+      authorizedKeys.markKeyInvalid(admin.id(), 1);
+      info = gApi.accounts().self().listSshKeys();
+      assertThat(info).hasSize(2);
+      assertThat(info.get(0).seq).isEqualTo(1);
+      assertThat(info.get(0).valid).isFalse();
+      assertThat(info.get(1).seq).isEqualTo(3);
+      accountIndexedCounter.assertReindexOf(admin);
+    }
   }
 
   @Test
   @UseSsh
   public void adminCanAddOrRemoveSshKeyOnOtherAccount() throws Exception {
-    // The test account should initially have exactly one ssh key
-    List<SshKeyInfo> info = gApi.accounts().self().listSshKeys();
-    assertThat(info).hasSize(1);
-    assertSequenceNumbers(info);
-    SshKeyInfo key = info.get(0);
-    KeyPair keyPair = sshKeys.getKeyPair(admin);
-    String initial = TestSshKeys.publicKey(keyPair, admin.email());
-    assertThat(key.sshPublicKey).isEqualTo(initial);
-    accountIndexedCounter.assertNoReindex();
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      // The test account should initially have exactly one ssh key
+      List<SshKeyInfo> info = gApi.accounts().self().listSshKeys();
+      assertThat(info).hasSize(1);
+      assertSequenceNumbers(info);
+      SshKeyInfo key = info.get(0);
+      KeyPair keyPair = sshKeys.getKeyPair(admin);
+      String initial = TestSshKeys.publicKey(keyPair, admin.email());
+      assertThat(key.sshPublicKey).isEqualTo(initial);
+      accountIndexedCounter.assertNoReindex();
 
-    // Add a new key
-    sender.clear();
-    String newKey = TestSshKeys.publicKey(TestSshKeys.genSshKey(), user.email());
-    gApi.accounts().id(user.username()).addSshKey(newKey);
-    info = gApi.accounts().id(user.username()).listSshKeys();
-    assertThat(info).hasSize(2);
-    assertSequenceNumbers(info);
-    accountIndexedCounter.assertReindexOf(user);
+      // Add a new key
+      sender.clear();
+      String newKey = TestSshKeys.publicKey(TestSshKeys.genSshKey(), user.email());
+      gApi.accounts().id(user.username()).addSshKey(newKey);
+      info = gApi.accounts().id(user.username()).listSshKeys();
+      assertThat(info).hasSize(2);
+      assertSequenceNumbers(info);
+      accountIndexedCounter.assertReindexOf(user);
 
-    assertThat(sender.getMessages()).hasSize(1);
-    Message message = sender.getMessages().get(0);
-    assertThat(message.rcpt()).containsExactly(user.getEmailAddress());
-    assertThat(message.body()).contains("new SSH keys have been added");
+      assertThat(sender.getMessages()).hasSize(1);
+      Message message = sender.getMessages().get(0);
+      assertThat(message.rcpt()).containsExactly(user.getEmailAddress());
+      assertThat(message.body()).contains("new SSH keys have been added");
 
-    // Delete key
-    sender.clear();
-    gApi.accounts().id(user.username()).deleteSshKey(1);
-    info = gApi.accounts().id(user.username()).listSshKeys();
-    assertThat(info).hasSize(1);
-    accountIndexedCounter.assertReindexOf(user);
+      // Delete key
+      sender.clear();
+      gApi.accounts().id(user.username()).deleteSshKey(1);
+      info = gApi.accounts().id(user.username()).listSshKeys();
+      assertThat(info).hasSize(1);
+      accountIndexedCounter.assertReindexOf(user);
 
-    assertThat(sender.getMessages()).hasSize(1);
-    message = sender.getMessages().get(0);
-    assertThat(message.rcpt()).containsExactly(user.getEmailAddress());
-    assertThat(message.body()).contains("SSH keys have been deleted");
+      assertThat(sender.getMessages()).hasSize(1);
+      message = sender.getMessages().get(0);
+      assertThat(message.rcpt()).containsExactly(user.getEmailAddress());
+      assertThat(message.body()).contains("SSH keys have been deleted");
+    }
   }
 
   @Test
@@ -2385,20 +2558,24 @@
   // reindex is tested by {@link AbstractQueryAccountsTest#reindex}
   @Test
   public void reindexPermissions() throws Exception {
-    // admin can reindex any account
-    requestScopeOperations.setApiUser(admin.id());
-    gApi.accounts().id(user.username()).index();
-    accountIndexedCounter.assertReindexOf(user);
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      // admin can reindex any account
+      requestScopeOperations.setApiUser(admin.id());
+      gApi.accounts().id(user.username()).index();
+      accountIndexedCounter.assertReindexOf(user);
 
-    // user can reindex own account
-    requestScopeOperations.setApiUser(user.id());
-    gApi.accounts().self().index();
-    accountIndexedCounter.assertReindexOf(user);
+      // user can reindex own account
+      requestScopeOperations.setApiUser(user.id());
+      gApi.accounts().self().index();
+      accountIndexedCounter.assertReindexOf(user);
 
-    // user cannot reindex any account
-    AuthException thrown =
-        assertThrows(AuthException.class, () -> gApi.accounts().id(admin.username()).index());
-    assertThat(thrown).hasMessageThat().contains("modify account not permitted");
+      // user cannot reindex any account
+      AuthException thrown =
+          assertThrows(AuthException.class, () -> gApi.accounts().id(admin.username()).index());
+      assertThat(thrown).hasMessageThat().contains("modify account not permitted");
+    }
   }
 
   @Test
@@ -3266,17 +3443,21 @@
   }
 
   private void addExternalIdEmail(TestAccount account, String email) throws Exception {
-    requireNonNull(email);
-    accountsUpdateProvider
-        .get()
-        .update(
-            "Add Email",
-            account.id(),
-            u ->
-                u.addExternalId(
-                    ExternalId.createWithEmail(name("test"), email, account.id(), email)));
-    accountIndexedCounter.assertReindexOf(account);
-    requestScopeOperations.setApiUser(account.id());
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      requireNonNull(email);
+      accountsUpdateProvider
+          .get()
+          .update(
+              "Add Email",
+              account.id(),
+              u ->
+                  u.addExternalId(
+                      ExternalId.createWithEmail(name("test"), email, account.id(), email)));
+      accountIndexedCounter.assertReindexOf(account);
+      requestScopeOperations.setApiUser(account.id());
+    }
   }
 
   private Map<String, GpgKeyInfo> addGpgKey(String armored) throws Exception {
@@ -3284,12 +3465,16 @@
   }
 
   private Map<String, GpgKeyInfo> addGpgKey(TestAccount account, String armored) throws Exception {
-    Map<String, GpgKeyInfo> gpgKeys =
-        gApi.accounts()
-            .id(account.username())
-            .putGpgKeys(ImmutableList.of(armored), ImmutableList.<String>of());
-    accountIndexedCounter.assertReindexOf(gApi.accounts().id(account.username()).get());
-    return gpgKeys;
+    AccountIndexedCounter accountIndexedCounter = new AccountIndexedCounter();
+    try (Registration registration =
+        extensionRegistry.newRegistration().add(accountIndexedCounter)) {
+      Map<String, GpgKeyInfo> gpgKeys =
+          gApi.accounts()
+              .id(account.username())
+              .putGpgKeys(ImmutableList.of(armored), ImmutableList.<String>of());
+      accountIndexedCounter.assertReindexOf(gApi.accounts().id(account.username()).get());
+      return gpgKeys;
+    }
   }
 
   private Map<String, GpgKeyInfo> addGpgKeyNoReindex(String armored) throws Exception {
diff --git a/javatests/com/google/gerrit/acceptance/api/group/GroupsIT.java b/javatests/com/google/gerrit/acceptance/api/group/GroupsIT.java
index 599a2b9..ba8bb7a 100644
--- a/javatests/com/google/gerrit/acceptance/api/group/GroupsIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/group/GroupsIT.java
@@ -38,6 +38,8 @@
 import com.google.common.truth.Correspondence;
 import com.google.common.util.concurrent.AtomicLongMap;
 import com.google.gerrit.acceptance.AbstractDaemonTest;
+import com.google.gerrit.acceptance.ExtensionRegistry;
+import com.google.gerrit.acceptance.ExtensionRegistry.Registration;
 import com.google.gerrit.acceptance.GerritConfig;
 import com.google.gerrit.acceptance.GitUtil;
 import com.google.gerrit.acceptance.NoHttpd;
@@ -66,8 +68,6 @@
 import com.google.gerrit.extensions.common.GroupInfo;
 import com.google.gerrit.extensions.common.GroupOptionsInfo;
 import com.google.gerrit.extensions.events.GroupIndexedListener;
-import com.google.gerrit.extensions.registration.DynamicSet;
-import com.google.gerrit.extensions.registration.RegistrationHandle;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
@@ -127,7 +127,6 @@
 public class GroupsIT extends AbstractDaemonTest {
   @Inject @ServerInitiated private GroupsUpdate groupsUpdate;
   @Inject private AccountOperations accountOperations;
-  @Inject private DynamicSet<GroupIndexedListener> groupIndexedListeners;
   @Inject private GroupIncludeCache groupIncludeCache;
   @Inject private GroupIndexer groupIndexer;
   @Inject private GroupOperations groupOperations;
@@ -138,6 +137,7 @@
   @Inject private RequestScopeOperations requestScopeOperations;
   @Inject private Sequences seq;
   @Inject private StalenessChecker stalenessChecker;
+  @Inject private ExtensionRegistry extensionRegistry;
 
   @After
   public void consistencyCheck() throws Exception {
@@ -1334,9 +1334,7 @@
     restartAsSlave();
 
     GroupIndexedCounter groupIndexedCounter = new GroupIndexedCounter();
-    RegistrationHandle groupIndexEventCounterHandle =
-        groupIndexedListeners.add("gerrit", groupIndexedCounter);
-    try {
+    try (Registration registration = extensionRegistry.newRegistration().add(groupIndexedCounter)) {
       // Running the reindexer right after startup should not need to reindex any group since
       // reindexing was already done on startup.
       slaveGroupIndexer.run();
@@ -1372,8 +1370,6 @@
       }
       slaveGroupIndexer.run();
       groupIndexedCounter.assertReindexOf(groupUuid);
-    } finally {
-      groupIndexEventCounterHandle.remove();
     }
   }
 
@@ -1391,14 +1387,10 @@
     restartAsSlave();
 
     GroupIndexedCounter groupIndexedCounter = new GroupIndexedCounter();
-    RegistrationHandle groupIndexEventCounterHandle =
-        groupIndexedListeners.add("gerrit", groupIndexedCounter);
-    try {
+    try (Registration registration = extensionRegistry.newRegistration().add(groupIndexedCounter)) {
       // No group indexing happened on startup. All groups should be reindexed now.
       slaveGroupIndexer.run();
       groupIndexedCounter.assertReindexOf(expectedGroups);
-    } finally {
-      groupIndexEventCounterHandle.remove();
     }
   }
 
diff --git a/javatests/com/google/gerrit/acceptance/api/revision/RevisionIT.java b/javatests/com/google/gerrit/acceptance/api/revision/RevisionIT.java
index 2087f939..b7517a0 100644
--- a/javatests/com/google/gerrit/acceptance/api/revision/RevisionIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/revision/RevisionIT.java
@@ -40,6 +40,8 @@
 import com.google.common.collect.Iterators;
 import com.google.common.collect.ListMultimap;
 import com.google.gerrit.acceptance.AbstractDaemonTest;
+import com.google.gerrit.acceptance.ExtensionRegistry;
+import com.google.gerrit.acceptance.ExtensionRegistry.Registration;
 import com.google.gerrit.acceptance.PushOneCommit;
 import com.google.gerrit.acceptance.RestResponse;
 import com.google.gerrit.acceptance.TestAccount;
@@ -117,11 +119,11 @@
 import org.junit.Test;
 
 public class RevisionIT extends AbstractDaemonTest {
-  @Inject private DynamicSet<ChangeIndexedListener> changeIndexedListeners;
   @Inject private DynamicSet<PatchSetWebLink> patchSetLinks;
   @Inject private GetRevisionActions getRevisionActions;
   @Inject private ProjectOperations projectOperations;
   @Inject private RequestScopeOperations requestScopeOperations;
+  @Inject private ExtensionRegistry extensionRegistry;
 
   @Test
   public void reviewTriplet() throws Exception {
@@ -1079,25 +1081,22 @@
 
     // Using the API returns the correct value, and reindexes as well.
     CountDownLatch reindexed = new CountDownLatch(1);
-    RegistrationHandle handle =
-        changeIndexedListeners.add(
-            "gerrit",
-            new ChangeIndexedListener() {
-              @Override
-              public void onChangeIndexed(String projectName, int id) {
-                if (id == id2.get()) {
-                  reindexed.countDown();
-                }
-              }
+    ChangeIndexedListener listener =
+        new ChangeIndexedListener() {
+          @Override
+          public void onChangeIndexed(String projectName, int id) {
+            if (id == id2.get()) {
+              reindexed.countDown();
+            }
+          }
 
-              @Override
-              public void onChangeDeleted(int id) {}
-            });
-    try {
+          @Override
+          public void onChangeDeleted(int id) {}
+        };
+
+    try (Registration registration = extensionRegistry.newRegistration().add(listener)) {
       assertMergeable(r2.getChangeId(), true);
       reindexed.await();
-    } finally {
-      handle.remove();
     }
 
     List<ChangeInfo> changes = search.call();
diff --git a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.html b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.html
index e8297af..2994c8d 100644
--- a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.html
+++ b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.html
@@ -121,10 +121,6 @@
       .changeMetadata {
         border-right: 1px solid var(--border-color);
       }
-      /* Prevent plugin text from overflowing. */
-      #change_plugins {
-        word-break: break-word;
-      }
       .commitMessage {
         font-family: var(--monospace-font-family);
         margin-right: 1em;
@@ -438,10 +434,6 @@
               parent-is-current="[[_parentIsCurrent]]"
               on-show-reply-dialog="_handleShowReplyDialog">
           </gr-change-metadata>
-          <!-- Plugins insert content into following container.
-               Stop-gap until PolyGerrit plugins interface is ready.
-               This will not work with Shadow DOM. -->
-          <div id="change_plugins"></div>
         </div>
         <div id="mainChangeInfo" class="changeInfo-column mainChangeInfo">
           <div id="commitAndRelated" class="hideOnMobileOverlay">
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-cursor/gr-diff-cursor.js b/polygerrit-ui/app/elements/diff/gr-diff-cursor/gr-diff-cursor.js
index e3a4821..a18d2f4 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-cursor/gr-diff-cursor.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-cursor/gr-diff-cursor.js
@@ -194,9 +194,13 @@
     },
 
     getTargetDiffElement() {
-      // Find the parent diff element of the cursor row.
-      for (let diff = this.diffRow; diff; diff = diff.parentElement) {
-        if (diff.tagName === 'GR-DIFF') { return diff; }
+      if (!this.diffRow) return null;
+
+      const hostOwner = Polymer.dom(/** @type {Node} */ (this.diffRow))
+        .getOwnerRoot();
+      if (hostOwner && hostOwner.host &&
+          hostOwner.host.tagName === 'GR-DIFF') {
+        return hostOwner.host;
       }
       return null;
     },
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-cursor/gr-diff-cursor_test.html b/polygerrit-ui/app/elements/diff/gr-diff-cursor/gr-diff-cursor_test.html
index 7280f2f..ffb5efa 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-cursor/gr-diff-cursor_test.html
+++ b/polygerrit-ui/app/elements/diff/gr-diff-cursor/gr-diff-cursor_test.html
@@ -249,6 +249,15 @@
       diffElement._diffChanged(mockDiffResponse.diffResponse);
     });
 
+    test('getTargetDiffElement', () => {
+      cursorElement.initialLineNumber = 1;
+      assert.isTrue(!!cursorElement.diffRow);
+      assert.equal(
+          cursorElement.getTargetDiffElement(),
+          diffElement
+      );
+    });
+
     test('getAddress', () => {
       // It should initialize to the first chunk: line 5 of the revision.
       assert.deepEqual(cursorElement.getAddress(),
diff --git a/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.html b/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.html
index 46877d7..1fa3db1 100644
--- a/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.html
+++ b/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.html
@@ -77,30 +77,13 @@
         on-blur="_onInputBlur"
         autocomplete="off">
 
-      <template is="dom-if" if="[[_isPolymer2()]]">
-        <!-- Content uses vertical-align:baseline. If iron-icon is placed
-          directly in the slot and is not visible,  vertical-align doesn't
-          work, because display:none convert it from inline-block element to
-          block element. To fix this problem, iron-icon is wrapped in div
-          which never changes display type.
-          The problem doesn't exist in Polymer1 because DOM is different.
-          Applying the same fix to Polymer1 breaks vertical-align.
-        -->
-        <div slot="prefix">
-          <iron-icon
-            icon="gr-icons:search"
-            class$="searchIcon [[_computeShowSearchIconClass(showSearchIcon)]]">
-          </iron-icon>
-        </div>
-      </template>
-      <template is="dom-if" if="[[!_isPolymer2()]]">
+      <!-- prefix as attribute is required to for polymer 1 -->
+      <div slot="prefix" prefix>
         <iron-icon
-          prefix
           icon="gr-icons:search"
           class$="searchIcon [[_computeShowSearchIconClass(showSearchIcon)]]">
         </iron-icon>
-      </template>
-
+      </div>
     </paper-input>
     <gr-autocomplete-dropdown
         vertical-align="top"
diff --git a/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.js b/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.js
index 745cff1..d422df8 100644
--- a/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.js
+++ b/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.js
@@ -196,7 +196,7 @@
     },
 
     focus() {
-      this.$.input.focus();
+      this._nativeInput.focus();
     },
 
     selectAll() {
@@ -330,7 +330,7 @@
         default:
           // For any normal keypress, return focus to the input to allow for
           // unbroken user input.
-          this.$.input.inputElement.focus();
+          this.focus();
 
           // Since this has been a normal keypress, the suggestions will have
           // been based on a previous input. Clear them. This prevents an
@@ -430,9 +430,5 @@
     _computeShowSearchIconClass(showSearchIcon) {
       return showSearchIcon ? 'showSearchIcon' : '';
     },
-
-    _isPolymer2() {
-      return window.POLYMER2;
-    },
   });
 })();
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-api-utils.js b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-api-utils.js
new file mode 100644
index 0000000..cf2376e
--- /dev/null
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-api-utils.js
@@ -0,0 +1,95 @@
+/**
+ * @license
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+(function(window) {
+  'use strict';
+
+  const PRELOADED_PROTOCOL = 'preloaded:';
+
+  let _restAPI;
+
+  const getRestAPI = () => {
+    if (!_restAPI) {
+      _restAPI = document.createElement('gr-rest-api-interface');
+    }
+    return _restAPI;
+  };
+
+  function getPluginNameFromUrl(url) {
+    if (!(url instanceof URL)) {
+      try {
+        url = new URL(url);
+      } catch (e) {
+        console.warn(e);
+        return null;
+      }
+    }
+    if (url.protocol === PRELOADED_PROTOCOL) {
+      return url.pathname;
+    }
+    const base = Gerrit.BaseUrlBehavior.getBaseUrl();
+    const pathname = url.pathname.replace(base, '');
+    // Site theme is server from predefined path.
+    if (pathname === '/static/gerrit-theme.html') {
+      return 'gerrit-theme';
+    } else if (!pathname.startsWith('/plugins')) {
+      console.warn('Plugin not being loaded from /plugins base path:',
+          url.href, '— Unable to determine name.');
+      return null;
+    }
+    // Pathname should normally look like this:
+    // /plugins/PLUGINNAME/static/SCRIPTNAME.html
+    // Or, for app/samples:
+    // /plugins/PLUGINNAME.html
+    return pathname.split('/')[2].split('.')[0];
+  }
+
+  // TODO (viktard): deprecate in favor of GrPluginRestApi.
+  function send(method, url, opt_callback, opt_payload) {
+    return getRestAPI().send(method, url, opt_payload).then(response => {
+      if (response.status < 200 || response.status >= 300) {
+        return response.text().then(text => {
+          if (text) {
+            return Promise.reject(text);
+          } else {
+            return Promise.reject(response.status);
+          }
+        });
+      } else {
+        return getRestAPI().getResponseObject(response);
+      }
+    }).then(response => {
+      if (opt_callback) {
+        opt_callback(response);
+      }
+      return response;
+    });
+  }
+
+  function resetInternalState() {
+    _restAPI = null;
+  }
+
+  window._apiUtils = {
+    getPluginNameFromUrl,
+    send,
+    getRestAPI,
+
+    // TEST only methods
+    resetInternalState,
+  };
+})(window);
\ No newline at end of file
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-api-utils_test.html b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-api-utils_test.html
new file mode 100644
index 0000000..c407aa8
--- /dev/null
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-api-utils_test.html
@@ -0,0 +1,78 @@
+<!DOCTYPE html>
+<!--
+@license
+Copyright (C) 2019 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+
+<meta name="viewport" content="width=device-width, minimum-scale=1.0, initial-scale=1.0, user-scalable=yes">
+<title>gr-api-interface</title>
+<script src="/test/common-test-setup.js"></script>
+<script src="/bower_components/webcomponentsjs/custom-elements-es5-adapter.js"></script>
+
+<script src="/bower_components/webcomponentsjs/webcomponents-lite.js"></script>
+<script src="/bower_components/web-component-tester/browser.js"></script>
+<link rel="import" href="../../../test/common-test-setup.html"/>
+<link rel="import" href="gr-js-api-interface.html">
+
+<script>void(0);</script>
+
+<script>
+
+  const PRELOADED_PROTOCOL = 'preloaded:';
+
+  suite('gr-api-utils tests', () => {
+    suite('test getPluginNameFromUrl', () => {
+      const {getPluginNameFromUrl} = window._apiUtils;
+
+      test('with empty string', () => {
+        assert.equal(getPluginNameFromUrl(''), null);
+      });
+
+      test('with invalid url', () => {
+        assert.equal(getPluginNameFromUrl('test'), null);
+      });
+
+      test('with random invalid url', () => {
+        assert.equal(getPluginNameFromUrl('http://example.com'), null);
+        assert.equal(
+            getPluginNameFromUrl('http://example.com/static/a.html'),
+            null
+        );
+      });
+
+      test('with valid urls', () => {
+        assert.equal(
+            getPluginNameFromUrl('http://example.com/plugins/a.html'),
+            'a'
+        );
+        assert.equal(
+            getPluginNameFromUrl('http://example.com/plugins/a/static/t.html'),
+            'a'
+        );
+      });
+
+      test('with preloaded urls', () => {
+        assert.equal(getPluginNameFromUrl(`${PRELOADED_PROTOCOL}a`), 'a');
+      });
+
+      test('with gerrit-theme override', () => {
+        assert.equal(
+            getPluginNameFromUrl('http://example.com/static/gerrit-theme.html'),
+            'gerrit-theme'
+        );
+      });
+    });
+  });
+</script>
\ No newline at end of file
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-gerrit.js b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-gerrit.js
new file mode 100644
index 0000000..8cdbcb7
--- /dev/null
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-gerrit.js
@@ -0,0 +1,280 @@
+/**
+ * @license
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+(function(window) {
+  'use strict';
+
+  /**
+   * Hash of loaded and installed plugins, name to Plugin object.
+   */
+  const _plugins = {};
+
+  /**
+   * Array of plugin URLs to be loaded, name to url.
+   */
+  let _pluginsPending = {};
+
+  let _pluginsInstalled = [];
+
+  let _pluginsPendingCount = -1;
+
+  const UNKNOWN_PLUGIN = 'unknown';
+  const PRELOADED_PROTOCOL = 'preloaded:';
+
+  const PLUGIN_LOADING_TIMEOUT_MS = 10000;
+
+  let _reporting;
+  const getReporting = () => {
+    if (!_reporting) {
+      _reporting = document.createElement('gr-reporting');
+    }
+    return _reporting;
+  };
+
+  // Import utils methods
+  const {
+      getPluginNameFromUrl,
+      send,
+      getRestAPI,
+      resetInternalState,
+  } = window._apiUtils;
+
+  const API_VERSION = '0.1';
+
+  window.Gerrit = window.Gerrit || {};
+  const Gerrit = window.Gerrit;
+
+  let _resolveAllPluginsLoaded = null;
+  let _allPluginsPromise = null;
+
+  Gerrit._endpoints = new GrPluginEndpoints();
+
+  // Provide reset plugins function to clear installed plugins between tests.
+  const app = document.querySelector('#app');
+  if (!app) {
+    // No gr-app found (running tests)
+    Gerrit._installPreloadedPlugins = installPreloadedPlugins;
+    Gerrit._flushPreinstalls = flushPreinstalls;
+    Gerrit._resetPlugins = () => {
+      _allPluginsPromise = null;
+      _pluginsInstalled = [];
+      _pluginsPending = {};
+      _pluginsPendingCount = -1;
+      _reporting = null;
+      _resolveAllPluginsLoaded = null;
+      resetInternalState();
+      Gerrit._endpoints = new GrPluginEndpoints();
+      for (const k of Object.keys(_plugins)) {
+        delete _plugins[k];
+      }
+    };
+  }
+
+  /**
+   * @deprecated Use plugin.styles().css(rulesStr) instead. Please, consult
+   * the documentation how to replace it accordingly.
+   */
+  Gerrit.css = function(rulesStr) {
+    console.warn('Gerrit.css(rulesStr) is deprecated!',
+        'Use plugin.styles().css(rulesStr)');
+    if (!Gerrit._customStyleSheet) {
+      const styleEl = document.createElement('style');
+      document.head.appendChild(styleEl);
+      Gerrit._customStyleSheet = styleEl.sheet;
+    }
+
+    const name = '__pg_js_api_class_' +
+        Gerrit._customStyleSheet.cssRules.length;
+    Gerrit._customStyleSheet.insertRule('.' + name + '{' + rulesStr + '}', 0);
+    return name;
+  };
+
+  Gerrit.install = function(callback, opt_version, opt_src) {
+    // HTML import polyfill adds __importElement pointing to the import tag.
+    const script = document.currentScript &&
+        (document.currentScript.__importElement || document.currentScript);
+
+    let src = opt_src || (script && script.src);
+    if (!src || src.startsWith('data:')) {
+      src = script && script.baseURI;
+    }
+    const name = getPluginNameFromUrl(src);
+
+    if (opt_version && opt_version !== API_VERSION) {
+      Gerrit._pluginInstallError(`Plugin ${name} install error: only version ` +
+          API_VERSION + ' is supported in PolyGerrit. ' + opt_version +
+          ' was given.');
+      return;
+    }
+
+    const existingPlugin = _plugins[name];
+    const plugin = existingPlugin || new Plugin(src);
+    try {
+      callback(plugin);
+      if (name) {
+        _plugins[name] = plugin;
+      }
+      if (!existingPlugin) {
+        Gerrit._pluginInstalled(src);
+      }
+    } catch (e) {
+      Gerrit._pluginInstallError(`${e.name}: ${e.message}`);
+    }
+  };
+
+  Gerrit.getLoggedIn = function() {
+    console.warn('Gerrit.getLoggedIn() is deprecated! ' +
+        'Use plugin.restApi().getLoggedIn()');
+    return document.createElement('gr-rest-api-interface').getLoggedIn();
+  };
+
+  Gerrit.get = function(url, callback) {
+    console.warn('.get() is deprecated! Use plugin.restApi().get()');
+    send('GET', url, callback);
+  };
+
+  Gerrit.post = function(url, payload, callback) {
+    console.warn('.post() is deprecated! Use plugin.restApi().post()');
+    send('POST', url, callback, payload);
+  };
+
+  Gerrit.put = function(url, payload, callback) {
+    console.warn('.put() is deprecated! Use plugin.restApi().put()');
+    send('PUT', url, callback, payload);
+  };
+
+  Gerrit.delete = function(url, opt_callback) {
+    console.warn('.delete() is deprecated! Use plugin.restApi().delete()');
+    return getRestAPI().send('DELETE', url).then(response => {
+      if (response.status !== 204) {
+        return response.text().then(text => {
+          if (text) {
+            return Promise.reject(text);
+          } else {
+            return Promise.reject(response.status);
+          }
+        });
+      }
+      if (opt_callback) {
+        opt_callback(response);
+      }
+      return response;
+    });
+  };
+
+  Gerrit.awaitPluginsLoaded = function() {
+    if (!_allPluginsPromise) {
+      if (Gerrit._arePluginsLoaded()) {
+        _allPluginsPromise = Promise.resolve();
+      } else {
+        let timeoutId;
+        _allPluginsPromise =
+          Promise.race([
+            new Promise(resolve => _resolveAllPluginsLoaded = resolve),
+            new Promise(resolve => timeoutId = setTimeout(
+                Gerrit._pluginLoadingTimeout, PLUGIN_LOADING_TIMEOUT_MS)),
+          ]).then(() => clearTimeout(timeoutId));
+      }
+    }
+    return _allPluginsPromise;
+  };
+
+  Gerrit._pluginLoadingTimeout = function() {
+    console.error(`Failed to load plugins: ${Object.keys(_pluginsPending)}`);
+    Gerrit._setPluginsPending([]);
+  };
+
+  Gerrit._setPluginsPending = function(plugins) {
+    _pluginsPending = plugins.reduce((o, url) => {
+      // TODO(viktard): Remove guard (@see Issue 8962)
+      o[getPluginNameFromUrl(url) || UNKNOWN_PLUGIN] = url;
+      return o;
+    }, {});
+    Gerrit._setPluginsCount(Object.keys(_pluginsPending).length);
+  };
+
+  Gerrit._setPluginsCount = function(count) {
+    _pluginsPendingCount = count;
+    if (Gerrit._arePluginsLoaded()) {
+      getReporting().pluginsLoaded(_pluginsInstalled);
+      if (_resolveAllPluginsLoaded) {
+        _resolveAllPluginsLoaded();
+      }
+    }
+  };
+
+  Gerrit._pluginInstallError = function(message) {
+    document.dispatchEvent(new CustomEvent('show-alert', {
+      detail: {
+        message: `Plugin install error: ${message}`,
+      },
+    }));
+    console.info(`Plugin install error: ${message}`);
+    Gerrit._setPluginsCount(_pluginsPendingCount - 1);
+  };
+
+  Gerrit._pluginInstalled = function(url) {
+    const name = getPluginNameFromUrl(url) || UNKNOWN_PLUGIN;
+    if (!_pluginsPending[name]) {
+      console.warn(`Unexpected plugin ${name} installed from ${url}.`);
+    } else {
+      delete _pluginsPending[name];
+      _pluginsInstalled.push(name);
+      Gerrit._setPluginsCount(_pluginsPendingCount - 1);
+      getReporting().pluginLoaded(name);
+      console.log(`Plugin ${name} installed.`);
+    }
+  };
+
+  Gerrit._arePluginsLoaded = function() {
+    return _pluginsPendingCount === 0;
+  };
+
+  Gerrit._getPluginScreenName = function(pluginName, screenName) {
+    return `${pluginName}-screen-${screenName}`;
+  };
+
+  Gerrit._isPluginPreloaded = function(url) {
+    const name = getPluginNameFromUrl(url);
+    if (name && Gerrit._preloadedPlugins) {
+      return name in Gerrit._preloadedPlugins;
+    } else {
+      return false;
+    }
+  };
+
+  function flushPreinstalls() {
+    if (window.Gerrit.flushPreinstalls) {
+      window.Gerrit.flushPreinstalls();
+    }
+  }
+
+  function installPreloadedPlugins() {
+    if (!Gerrit._preloadedPlugins) { return; }
+    for (const name in Gerrit._preloadedPlugins) {
+      if (!Gerrit._preloadedPlugins.hasOwnProperty(name)) { continue; }
+      const callback = Gerrit._preloadedPlugins[name];
+      Gerrit.install(callback, API_VERSION, PRELOADED_PROTOCOL + name);
+    }
+  }
+
+  flushPreinstalls();
+
+  // Preloaded plugins should be installed after Gerrit.install() is set,
+  // since plugin preloader substitutes Gerrit.install() temporarily.
+  installPreloadedPlugins();
+})(window);
\ No newline at end of file
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-gerrit_test.html b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-gerrit_test.html
new file mode 100644
index 0000000..b3ec30f
--- /dev/null
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-gerrit_test.html
@@ -0,0 +1,188 @@
+<!DOCTYPE html>
+<!--
+@license
+Copyright (C) 2019 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+
+<meta name="viewport" content="width=device-width, minimum-scale=1.0, initial-scale=1.0, user-scalable=yes">
+<title>gr-api-interface</title>
+<script src="/test/common-test-setup.js"></script>
+<script src="/bower_components/webcomponentsjs/custom-elements-es5-adapter.js"></script>
+
+<script src="/bower_components/webcomponentsjs/webcomponents-lite.js"></script>
+<script src="/bower_components/web-component-tester/browser.js"></script>
+<link rel="import" href="../../../test/common-test-setup.html"/>
+<link rel="import" href="gr-js-api-interface.html">
+
+<script>void(0);</script>
+
+<test-fixture id="basic">
+  <template>
+    <gr-js-api-interface></gr-js-api-interface>
+  </template>
+</test-fixture>
+
+<script>
+  suite('gr-gerrit tests', () => {
+    let element;
+    let plugin;
+    let sandbox;
+    let sendStub;
+
+    setup(() => {
+      sandbox = sinon.sandbox.create();
+      sendStub = sandbox.stub().returns(Promise.resolve({status: 200}));
+      stub('gr-rest-api-interface', {
+        getAccount() {
+          return Promise.resolve({name: 'Judy Hopps'});
+        },
+        send(...args) {
+          return sendStub(...args);
+        },
+      });
+      element = fixture('basic');
+      Gerrit.install(p => { plugin = p; }, '0.1',
+          'http://test.com/plugins/testplugin/static/test.js');
+      Gerrit._setPluginsPending([]);
+    });
+
+    teardown(() => {
+      sandbox.restore();
+      element._removeEventCallbacks();
+      plugin = null;
+    });
+
+    test('reuse plugin for install calls', () => {
+      let otherPlugin;
+      Gerrit.install(p => { otherPlugin = p; }, '0.1',
+          'http://test.com/plugins/testplugin/static/test.js');
+      assert.strictEqual(plugin, otherPlugin);
+    });
+
+    test('flushes preinstalls if provided', () => {
+      assert.doesNotThrow(() => {
+        Gerrit._flushPreinstalls();
+      });
+      window.Gerrit.flushPreinstalls = sandbox.stub();
+      Gerrit._flushPreinstalls();
+      assert.isTrue(window.Gerrit.flushPreinstalls.calledOnce);
+      delete window.Gerrit.flushPreinstalls;
+    });
+
+    test('versioning', () => {
+      const callback = sandbox.spy();
+      Gerrit.install(callback, '0.0pre-alpha');
+      assert(callback.notCalled);
+    });
+
+    test('_setPluginsCount', done => {
+      stub('gr-reporting', {
+        pluginsLoaded() {
+          done();
+        },
+      });
+      Gerrit._setPluginsCount(0);
+    });
+
+    test('_arePluginsLoaded', () => {
+      assert.isTrue(Gerrit._arePluginsLoaded());
+      Gerrit._setPluginsCount(1);
+      assert.isFalse(Gerrit._arePluginsLoaded());
+      Gerrit._setPluginsCount(0);
+      assert.isTrue(Gerrit._arePluginsLoaded());
+    });
+
+    test('_pluginInstalled', () => {
+      const pluginsLoadedStub = sandbox.stub();
+      stub('gr-reporting', {
+        pluginsLoaded: (...args) => pluginsLoadedStub(...args),
+      });
+      const plugins = [
+        'http://test.com/plugins/foo/static/test.js',
+        'http://test.com/plugins/bar/static/test.js',
+      ];
+      Gerrit._setPluginsPending(plugins);
+      Gerrit._pluginInstalled(plugins[0]);
+      Gerrit._pluginInstalled(plugins[1]);
+      assert.isTrue(pluginsLoadedStub.calledWithExactly(['foo', 'bar']));
+    });
+
+    test('install calls _pluginInstalled', () => {
+      sandbox.stub(Gerrit, '_pluginInstalled');
+      Gerrit.install(p => { plugin = p; }, '0.1',
+          'http://test.com/plugins/testplugin/static/test.js');
+
+      // testplugin has already been installed once (in setup).
+      assert.isFalse(Gerrit._pluginInstalled.called);
+
+      // testplugin2 plugin has not yet been installed.
+      Gerrit.install(p => { plugin = p; }, '0.1',
+          'http://test.com/plugins/testplugin2/static/test.js');
+      assert.isTrue(Gerrit._pluginInstalled.calledOnce);
+    });
+
+    test('plugin install errors mark plugins as loaded', () => {
+      Gerrit._setPluginsCount(1);
+      Gerrit.install(() => {}, '0.0pre-alpha');
+      return Gerrit.awaitPluginsLoaded();
+    });
+
+    test('multiple ui plugins per java plugin', () => {
+      const file1 = 'http://test.com/plugins/qaz/static/foo.nocache.js';
+      const file2 = 'http://test.com/plugins/qaz/static/bar.js';
+      Gerrit._setPluginsPending([file1, file2]);
+      Gerrit.install(() => {}, '0.1', file1);
+      Gerrit.install(() => {}, '0.1', file2);
+      return Gerrit.awaitPluginsLoaded();
+    });
+
+    test('plugin install errors shows toasts', () => {
+      const alertStub = sandbox.stub();
+      document.addEventListener('show-alert', alertStub);
+      Gerrit._setPluginsCount(1);
+      Gerrit.install(() => {}, '0.0pre-alpha');
+      return Gerrit.awaitPluginsLoaded().then(() => {
+        assert.isTrue(alertStub.calledOnce);
+      });
+    });
+
+    test('Gerrit._isPluginPreloaded', () => {
+      Gerrit._preloadedPlugins = {baz: ()=>{}};
+      assert.isFalse(Gerrit._isPluginPreloaded('plugins/foo/bar'));
+      assert.isFalse(Gerrit._isPluginPreloaded('http://a.com/42'));
+      assert.isTrue(Gerrit._isPluginPreloaded('preloaded:baz'));
+      Gerrit._preloadedPlugins = null;
+    });
+
+    test('preloaded plugins are installed', () => {
+      const installStub = sandbox.stub();
+      Gerrit._preloadedPlugins = {foo: installStub};
+      Gerrit._installPreloadedPlugins();
+      assert.isTrue(installStub.called);
+      const pluginApi = installStub.lastCall.args[0];
+      assert.strictEqual(pluginApi.getPluginName(), 'foo');
+    });
+
+    test('installing preloaded plugin', () => {
+      let plugin;
+      window.ASSETS_PATH = 'http://blips.com/chitz';
+      Gerrit.install(p => { plugin = p; }, '0.1', 'preloaded:foo');
+      assert.strictEqual(plugin.getPluginName(), 'foo');
+      assert.strictEqual(plugin.url('/some/thing.html'),
+          'http://blips.com/chitz/plugins/foo/some/thing.html');
+      delete window.ASSETS_PATH;
+    });
+  });
+</script>
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface.html b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface.html
index e460660..7fa2250 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface.html
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface.html
@@ -31,6 +31,7 @@
 <link rel="import" href="../gr-rest-api-interface/gr-rest-api-interface.html">
 
 <dom-module id="gr-js-api-interface">
+  <script src="gr-api-utils.js"></script>
   <script src="gr-annotation-actions-context.js"></script>
   <script src="gr-annotation-actions-js-api.js"></script>
   <script src="gr-change-actions-js-api.js"></script>
@@ -40,4 +41,5 @@
   <script src="gr-plugin-action-context.js"></script>
   <script src="gr-plugin-rest-api.js"></script>
   <script src="gr-public-js-api.js"></script>
+  <script src="gr-gerrit.js"></script>
 </dom-module>
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface_test.html b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface_test.html
index c7e4f09..330310f 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface_test.html
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface_test.html
@@ -73,23 +73,6 @@
       plugin = null;
     });
 
-    test('reuse plugin for install calls', () => {
-      let otherPlugin;
-      Gerrit.install(p => { otherPlugin = p; }, '0.1',
-          'http://test.com/plugins/testplugin/static/test.js');
-      assert.strictEqual(plugin, otherPlugin);
-    });
-
-    test('flushes preinstalls if provided', () => {
-      assert.doesNotThrow(() => {
-        Gerrit._flushPreinstalls();
-      });
-      window.Gerrit.flushPreinstalls = sandbox.stub();
-      Gerrit._flushPreinstalls();
-      assert.isTrue(window.Gerrit.flushPreinstalls.calledOnce);
-      delete window.Gerrit.flushPreinstalls;
-    });
-
     test('url', () => {
       assert.equal(plugin.url(), 'http://test.com/plugins/testplugin/');
       assert.equal(plugin.url('/static/test.js'),
@@ -313,12 +296,6 @@
       element.handleEvent(element.EventType.HIGHLIGHTJS_LOADED, {hljs: testHljs});
     });
 
-    test('versioning', () => {
-      const callback = sandbox.spy();
-      Gerrit.install(callback, '0.0pre-alpha');
-      assert(callback.notCalled);
-    });
-
     test('getAccount', done => {
       plugin.restApi().getLoggedIn().then(loggedIn => {
         assert.isTrue(loggedIn);
@@ -326,77 +303,6 @@
       });
     });
 
-    test('_setPluginsCount', done => {
-      stub('gr-reporting', {
-        pluginsLoaded() {
-          done();
-        },
-      });
-      Gerrit._setPluginsCount(0);
-    });
-
-    test('_arePluginsLoaded', () => {
-      assert.isTrue(Gerrit._arePluginsLoaded());
-      Gerrit._setPluginsCount(1);
-      assert.isFalse(Gerrit._arePluginsLoaded());
-      Gerrit._setPluginsCount(0);
-      assert.isTrue(Gerrit._arePluginsLoaded());
-    });
-
-    test('_pluginInstalled', () => {
-      const pluginsLoadedStub = sandbox.stub();
-      stub('gr-reporting', {
-        pluginsLoaded: (...args) => pluginsLoadedStub(...args),
-      });
-      const plugins = [
-        'http://test.com/plugins/foo/static/test.js',
-        'http://test.com/plugins/bar/static/test.js',
-      ];
-      Gerrit._setPluginsPending(plugins);
-      Gerrit._pluginInstalled(plugins[0]);
-      Gerrit._pluginInstalled(plugins[1]);
-      assert.isTrue(pluginsLoadedStub.calledWithExactly(['foo', 'bar']));
-    });
-
-    test('install calls _pluginInstalled', () => {
-      sandbox.stub(Gerrit, '_pluginInstalled');
-      Gerrit.install(p => { plugin = p; }, '0.1',
-          'http://test.com/plugins/testplugin/static/test.js');
-
-      // testplugin has already been installed once (in setup).
-      assert.isFalse(Gerrit._pluginInstalled.called);
-
-      // testplugin2 plugin has not yet been installed.
-      Gerrit.install(p => { plugin = p; }, '0.1',
-          'http://test.com/plugins/testplugin2/static/test.js');
-      assert.isTrue(Gerrit._pluginInstalled.calledOnce);
-    });
-
-    test('plugin install errors mark plugins as loaded', () => {
-      Gerrit._setPluginsCount(1);
-      Gerrit.install(() => {}, '0.0pre-alpha');
-      return Gerrit.awaitPluginsLoaded();
-    });
-
-    test('multiple ui plugins per java plugin', () => {
-      const file1 = 'http://test.com/plugins/qaz/static/foo.nocache.js';
-      const file2 = 'http://test.com/plugins/qaz/static/bar.js';
-      Gerrit._setPluginsPending([file1, file2]);
-      Gerrit.install(() => {}, '0.1', file1);
-      Gerrit.install(() => {}, '0.1', file2);
-      return Gerrit.awaitPluginsLoaded();
-    });
-
-    test('plugin install errors shows toasts', () => {
-      const alertStub = sandbox.stub();
-      document.addEventListener('show-alert', alertStub);
-      Gerrit._setPluginsCount(1);
-      Gerrit.install(() => {}, '0.0pre-alpha');
-      return Gerrit.awaitPluginsLoaded().then(() => {
-        assert.isTrue(alertStub.calledOnce);
-      });
-    });
-
     test('attributeHelper', () => {
       assert.isOk(plugin.attributeHelper());
     });
@@ -422,33 +328,6 @@
           element.EventType.ADMIN_MENU_LINKS);
     });
 
-    test('Gerrit._isPluginPreloaded', () => {
-      Gerrit._preloadedPlugins = {baz: ()=>{}};
-      assert.isFalse(Gerrit._isPluginPreloaded('plugins/foo/bar'));
-      assert.isFalse(Gerrit._isPluginPreloaded('http://a.com/42'));
-      assert.isTrue(Gerrit._isPluginPreloaded('preloaded:baz'));
-      Gerrit._preloadedPlugins = null;
-    });
-
-    test('preloaded plugins are installed', () => {
-      const installStub = sandbox.stub();
-      Gerrit._preloadedPlugins = {foo: installStub};
-      Gerrit._installPreloadedPlugins();
-      assert.isTrue(installStub.called);
-      const pluginApi = installStub.lastCall.args[0];
-      assert.strictEqual(pluginApi.getPluginName(), 'foo');
-    });
-
-    test('installing preloaded plugin', () => {
-      let plugin;
-      window.ASSETS_PATH = 'http://blips.com/chitz';
-      Gerrit.install(p => { plugin = p; }, '0.1', 'preloaded:foo');
-      assert.strictEqual(plugin.getPluginName(), 'foo');
-      assert.strictEqual(plugin.url('/some/thing.html'),
-          'http://blips.com/chitz/plugins/foo/some/thing.html');
-      delete window.ASSETS_PATH;
-    });
-
     suite('test plugin with base url', () => {
       let baseUrlPlugin;
 
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-public-js-api.js b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-public-js-api.js
index 3b7b80d..d44acea 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-public-js-api.js
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-public-js-api.js
@@ -17,71 +17,18 @@
 (function(window) {
   'use strict';
 
-  /**
-   * Hash of loaded and installed plugins, name to Plugin object.
-   */
-  const _plugins = {};
-
-  /**
-   * Array of plugin URLs to be loaded, name to url.
-   */
-  let _pluginsPending = {};
-
-  let _pluginsInstalled = [];
-
-  let _pluginsPendingCount = -1;
-
   const PRELOADED_PROTOCOL = 'preloaded:';
 
-  const UNKNOWN_PLUGIN = 'unknown';
-
   const PANEL_ENDPOINTS_MAPPING = {
     CHANGE_SCREEN_BELOW_COMMIT_INFO_BLOCK: 'change-view-integration',
     CHANGE_SCREEN_BELOW_CHANGE_INFO_BLOCK: 'change-metadata-item',
   };
 
-  const PLUGIN_LOADING_TIMEOUT_MS = 10000;
-
-  let _restAPI;
-
-  const getRestAPI = () => {
-    if (!_restAPI) {
-      _restAPI = document.createElement('gr-rest-api-interface');
-    }
-    return _restAPI;
-  };
-
-  let _reporting;
-  const getReporting = () => {
-    if (!_reporting) {
-      _reporting = document.createElement('gr-reporting');
-    }
-    return _reporting;
-  };
-
-  // TODO (viktard): deprecate in favor of GrPluginRestApi.
-  function send(method, url, opt_callback, opt_payload) {
-    return getRestAPI().send(method, url, opt_payload).then(response => {
-      if (response.status < 200 || response.status >= 300) {
-        return response.text().then(text => {
-          if (text) {
-            return Promise.reject(text);
-          } else {
-            return Promise.reject(response.status);
-          }
-        });
-      } else {
-        return getRestAPI().getResponseObject(response);
-      }
-    }).then(response => {
-      if (opt_callback) {
-        opt_callback(response);
-      }
-      return response;
-    });
-  }
-
-  const API_VERSION = '0.1';
+  // Import utils methods
+  const {
+      getPluginNameFromUrl,
+      send,
+  } = window._apiUtils;
 
   /**
    * Plugin-provided custom components can affect content in extension
@@ -99,50 +46,6 @@
     STYLE: 'style',
   };
 
-  function flushPreinstalls() {
-    if (window.Gerrit.flushPreinstalls) {
-      window.Gerrit.flushPreinstalls();
-    }
-  }
-
-  function installPreloadedPlugins() {
-    if (!Gerrit._preloadedPlugins) { return; }
-    for (const name in Gerrit._preloadedPlugins) {
-      if (!Gerrit._preloadedPlugins.hasOwnProperty(name)) { continue; }
-      const callback = Gerrit._preloadedPlugins[name];
-      Gerrit.install(callback, API_VERSION, PRELOADED_PROTOCOL + name);
-    }
-  }
-
-  function getPluginNameFromUrl(url) {
-    if (!(url instanceof URL)) {
-      try {
-        url = new URL(url);
-      } catch (e) {
-        console.warn(e);
-        return null;
-      }
-    }
-    if (url.protocol === PRELOADED_PROTOCOL) {
-      return url.pathname;
-    }
-    const base = Gerrit.BaseUrlBehavior.getBaseUrl();
-    const pathname = url.pathname.replace(base, '');
-    // Site theme is server from predefined path.
-    if (pathname === '/static/gerrit-theme.html') {
-      return 'gerrit-theme';
-    } else if (!pathname.startsWith('/plugins')) {
-      console.warn('Plugin not being loaded from /plugins base path:',
-          url.href, '— Unable to determine name.');
-      return;
-    }
-    // Pathname should normally look like this:
-    // /plugins/PLUGINNAME/static/SCRIPTNAME.html
-    // Or, for app/samples:
-    // /plugins/PLUGINNAME.html
-    return pathname.split('/')[2].split('.')[0];
-  }
-
   function Plugin(opt_url) {
     this._domHooks = new GrDomHooksManager(this);
 
@@ -475,211 +378,5 @@
     },
   };
 
-  flushPreinstalls();
-
-  window.Gerrit = window.Gerrit || {};
-  const Gerrit = window.Gerrit;
-
-  let _resolveAllPluginsLoaded = null;
-  let _allPluginsPromise = null;
-
-  Gerrit._endpoints = new GrPluginEndpoints();
-
-  // Provide reset plugins function to clear installed plugins between tests.
-  const app = document.querySelector('#app');
-  if (!app) {
-    // No gr-app found (running tests)
-    Gerrit._installPreloadedPlugins = installPreloadedPlugins;
-    Gerrit._flushPreinstalls = flushPreinstalls;
-    Gerrit._resetPlugins = () => {
-      _allPluginsPromise = null;
-      _pluginsInstalled = [];
-      _pluginsPending = {};
-      _pluginsPendingCount = -1;
-      _reporting = null;
-      _resolveAllPluginsLoaded = null;
-      _restAPI = null;
-      Gerrit._endpoints = new GrPluginEndpoints();
-      for (const k of Object.keys(_plugins)) {
-        delete _plugins[k];
-      }
-    };
-  }
-
-  /**
-   * @deprecated Use plugin.styles().css(rulesStr) instead. Please, consult
-   * the documentation how to replace it accordingly.
-   */
-  Gerrit.css = function(rulesStr) {
-    console.warn('Gerrit.css(rulesStr) is deprecated!',
-        'Use plugin.styles().css(rulesStr)');
-    if (!Gerrit._customStyleSheet) {
-      const styleEl = document.createElement('style');
-      document.head.appendChild(styleEl);
-      Gerrit._customStyleSheet = styleEl.sheet;
-    }
-
-    const name = '__pg_js_api_class_' +
-        Gerrit._customStyleSheet.cssRules.length;
-    Gerrit._customStyleSheet.insertRule('.' + name + '{' + rulesStr + '}', 0);
-    return name;
-  };
-
-  Gerrit.install = function(callback, opt_version, opt_src) {
-    // HTML import polyfill adds __importElement pointing to the import tag.
-    const script = document.currentScript &&
-        (document.currentScript.__importElement || document.currentScript);
-
-    let src = opt_src || (script && script.src);
-    if (!src || src.startsWith('data:')) {
-      src = script && script.baseURI;
-    }
-    const name = getPluginNameFromUrl(src);
-
-    if (opt_version && opt_version !== API_VERSION) {
-      Gerrit._pluginInstallError(`Plugin ${name} install error: only version ` +
-          API_VERSION + ' is supported in PolyGerrit. ' + opt_version +
-          ' was given.');
-      return;
-    }
-
-    const existingPlugin = _plugins[name];
-    const plugin = existingPlugin || new Plugin(src);
-    try {
-      callback(plugin);
-      if (name) {
-        _plugins[name] = plugin;
-      }
-      if (!existingPlugin) {
-        Gerrit._pluginInstalled(src);
-      }
-    } catch (e) {
-      Gerrit._pluginInstallError(`${e.name}: ${e.message}`);
-    }
-  };
-
-  Gerrit.getLoggedIn = function() {
-    console.warn('Gerrit.getLoggedIn() is deprecated! ' +
-        'Use plugin.restApi().getLoggedIn()');
-    return document.createElement('gr-rest-api-interface').getLoggedIn();
-  };
-
-  Gerrit.get = function(url, callback) {
-    console.warn('.get() is deprecated! Use plugin.restApi().get()');
-    send('GET', url, callback);
-  };
-
-  Gerrit.post = function(url, payload, callback) {
-    console.warn('.post() is deprecated! Use plugin.restApi().post()');
-    send('POST', url, callback, payload);
-  };
-
-  Gerrit.put = function(url, payload, callback) {
-    console.warn('.put() is deprecated! Use plugin.restApi().put()');
-    send('PUT', url, callback, payload);
-  };
-
-  Gerrit.delete = function(url, opt_callback) {
-    console.warn('.delete() is deprecated! Use plugin.restApi().delete()');
-    return getRestAPI().send('DELETE', url).then(response => {
-      if (response.status !== 204) {
-        return response.text().then(text => {
-          if (text) {
-            return Promise.reject(text);
-          } else {
-            return Promise.reject(response.status);
-          }
-        });
-      }
-      if (opt_callback) {
-        opt_callback(response);
-      }
-      return response;
-    });
-  };
-
-  Gerrit.awaitPluginsLoaded = function() {
-    if (!_allPluginsPromise) {
-      if (Gerrit._arePluginsLoaded()) {
-        _allPluginsPromise = Promise.resolve();
-      } else {
-        let timeoutId;
-        _allPluginsPromise =
-          Promise.race([
-            new Promise(resolve => _resolveAllPluginsLoaded = resolve),
-            new Promise(resolve => timeoutId = setTimeout(
-                Gerrit._pluginLoadingTimeout, PLUGIN_LOADING_TIMEOUT_MS)),
-          ]).then(() => clearTimeout(timeoutId));
-      }
-    }
-    return _allPluginsPromise;
-  };
-
-  Gerrit._pluginLoadingTimeout = function() {
-    console.error(`Failed to load plugins: ${Object.keys(_pluginsPending)}`);
-    Gerrit._setPluginsPending([]);
-  };
-
-  Gerrit._setPluginsPending = function(plugins) {
-    _pluginsPending = plugins.reduce((o, url) => {
-      // TODO(viktard): Remove guard (@see Issue 8962)
-      o[getPluginNameFromUrl(url) || UNKNOWN_PLUGIN] = url;
-      return o;
-    }, {});
-    Gerrit._setPluginsCount(Object.keys(_pluginsPending).length);
-  };
-
-  Gerrit._setPluginsCount = function(count) {
-    _pluginsPendingCount = count;
-    if (Gerrit._arePluginsLoaded()) {
-      getReporting().pluginsLoaded(_pluginsInstalled);
-      if (_resolveAllPluginsLoaded) {
-        _resolveAllPluginsLoaded();
-      }
-    }
-  };
-
-  Gerrit._pluginInstallError = function(message) {
-    document.dispatchEvent(new CustomEvent('show-alert', {
-      detail: {
-        message: `Plugin install error: ${message}`,
-      },
-    }));
-    console.info(`Plugin install error: ${message}`);
-    Gerrit._setPluginsCount(_pluginsPendingCount - 1);
-  };
-
-  Gerrit._pluginInstalled = function(url) {
-    const name = getPluginNameFromUrl(url) || UNKNOWN_PLUGIN;
-    if (!_pluginsPending[name]) {
-      console.warn(`Unexpected plugin ${name} installed from ${url}.`);
-    } else {
-      delete _pluginsPending[name];
-      _pluginsInstalled.push(name);
-      Gerrit._setPluginsCount(_pluginsPendingCount - 1);
-      getReporting().pluginLoaded(name);
-      console.log(`Plugin ${name} installed.`);
-    }
-  };
-
-  Gerrit._arePluginsLoaded = function() {
-    return _pluginsPendingCount === 0;
-  };
-
-  Gerrit._getPluginScreenName = function(pluginName, screenName) {
-    return `${pluginName}-screen-${screenName}`;
-  };
-
-  Gerrit._isPluginPreloaded = function(url) {
-    const name = getPluginNameFromUrl(url);
-    if (name && Gerrit._preloadedPlugins) {
-      return name in Gerrit._preloadedPlugins;
-    } else {
-      return false;
-    }
-  };
-
-  // Preloaded plugins should be installed after Gerrit.install() is set,
-  // since plugin preloader substitutes Gerrit.install() temporarily.
-  installPreloadedPlugins();
+  window.Plugin = Plugin;
 })(window);
diff --git a/polygerrit-ui/app/test/index.html b/polygerrit-ui/app/test/index.html
index 10d5aff..a0e85ef 100644
--- a/polygerrit-ui/app/test/index.html
+++ b/polygerrit-ui/app/test/index.html
@@ -188,7 +188,9 @@
     'shared/gr-js-api-interface/gr-annotation-actions-js-api_test.html',
     'shared/gr-js-api-interface/gr-change-actions-js-api_test.html',
     'shared/gr-js-api-interface/gr-change-reply-js-api_test.html',
+    'shared/gr-js-api-interface/gr-api-utils_test.html',
     'shared/gr-js-api-interface/gr-js-api-interface_test.html',
+    'shared/gr-js-api-interface/gr-gerrit_test.html',
     // TODO: uncomment file & fix tests. The file was missed in this list for a long time.
     // 'shared/gr-js-api-interface/gr-plugin-action-context_test.html',
     'shared/gr-js-api-interface/gr-plugin-endpoints_test.html',