[Signin][Android] Change getGoogleAccounts() return type to List

This CL changes AccountManagerFacade.getGoogleAccounts() return type
from Account[] to List<Account>. This is done to ensure immutability of
this list and for consistency with getGoogleAccountNames().

Bug: None
Change-Id: If703947028dd4ed0c9fdaf18856d97d6b6a52aa5
Reviewed-on: https://chromium-review.googlesource.com/c/1338088
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610026}

chrome/android/java/src/org/chromium/chrome/browser/IntentHelper.java

@@ -17,6 +17,7 @@ import org.chromium.base.annotations.CalledByNative;
 import org.chromium.components.signin.AccountManagerFacade;
 
 import java.io.File;
+import java.util.List;
 
 /**
  * Helper for issuing intents to the android framework.
@@ -40,10 +41,10 @@ public abstract class IntentHelper {
     static void sendEmail(
             String email, String subject, String body, String chooserTitle, String fileToAttach) {
         if (TextUtils.isEmpty(email)) {
-            Account[] accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
-            if (accounts != null && accounts.length == 1
-                    && Patterns.EMAIL_ADDRESS.matcher(accounts[0].name).matches()) {
-                email = accounts[0].name;
+            List<Account> accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
+            if (accounts != null && accounts.size() == 1
+                    && Patterns.EMAIL_ADDRESS.matcher(accounts.get(0).name).matches()) {
+                email = accounts.get(0).name;
             }
         }
 

chrome/android/java/src/org/chromium/chrome/browser/autofill_assistant/AutofillAssistantUiController.java

@@ -376,9 +376,9 @@ public class AutofillAssistantUiController implements AutofillAssistantUiDelegat
     /** Choose an account to authenticate as for making RPCs to the backend. */
     private void chooseAccountAsync(Bundle extras) {
         AccountManagerFacade.get().tryGetGoogleAccounts(accounts -> {
-            if (accounts.length == 1) {
+            if (accounts.size() == 1) {
                 // If there's only one account, there aren't any doubts.
-                onAccountChosen(accounts[0]);
+                onAccountChosen(accounts.get(0));
                 return;
             }
             Account signedIn =
@@ -414,8 +414,9 @@ public class AutofillAssistantUiController implements AutofillAssistantUiDelegat
         }
     }
 
-    private static Account findAccountByName(Account[] accounts, String name) {
-        for (Account account : accounts) {
+    private static Account findAccountByName(List<Account> accounts, String name) {
+        for (int i = 0; i < accounts.size(); i++) {
+            Account account = accounts.get(i);
             if (account.name.equals(name)) {
                 return account;
             }

chrome/android/java/src/org/chromium/chrome/browser/childaccounts/ChildAccountService.java

@@ -41,11 +41,11 @@ public class ChildAccountService {
         ThreadUtils.assertOnUiThread();
         final AccountManagerFacade accountManager = AccountManagerFacade.get();
         accountManager.tryGetGoogleAccounts(accounts -> {
-            if (accounts.length != 1) {
+            if (accounts.size() != 1) {
                 // Child accounts can't share a device.
                 callback.onResult(ChildAccountStatus.NOT_CHILD);
             } else {
-                accountManager.checkChildAccountStatus(accounts[0], callback);
+                accountManager.checkChildAccountStatus(accounts.get(0), callback);
             }
         });
     }

chrome/android/java/src/org/chromium/chrome/browser/firstrun/FirstRunFlowSequencer.java

@@ -60,7 +60,7 @@ public abstract class FirstRunFlowSequencer  {
     // The following are initialized via initializeSharedState().
     private boolean mIsAndroidEduDevice;
     private @ChildAccountStatus.Status int mChildAccountStatus;
-    private Account[] mGoogleAccounts;
+    private List<Account> mGoogleAccounts;
     private boolean mForceEduSignIn;
 
     /**
@@ -113,7 +113,7 @@ public abstract class FirstRunFlowSequencer  {
     }
 
     @VisibleForTesting
-    protected Account[] getGoogleAccounts() {
+    protected List<Account> getGoogleAccounts() {
         return AccountManagerFacade.get().tryGetGoogleAccounts();
     }
 
@@ -163,7 +163,7 @@ public abstract class FirstRunFlowSequencer  {
         mGoogleAccounts = getGoogleAccounts();
         // EDU devices should always have exactly 1 google account, which will be automatically
         // signed-in. All FRE screens are skipped in this case.
-        mForceEduSignIn = mIsAndroidEduDevice && mGoogleAccounts.length == 1 && !isSignedIn();
+        mForceEduSignIn = mIsAndroidEduDevice && mGoogleAccounts.size() == 1 && !isSignedIn();
     }
 
     void processFreEnvironmentPreNative() {
@@ -195,7 +195,7 @@ public abstract class FirstRunFlowSequencer  {
 
     /**
      * Called onNativeInitialized() a given flow as completed.
-     * @param data Resulting FRE properties bundle.
+     * @param freProperties Resulting FRE properties bundle.
      */
     public void onNativeInitialized(Bundle freProperties) {
         // We show the sign-in page if sync is allowed, and not signed in, and this is not
@@ -203,13 +203,13 @@ public abstract class FirstRunFlowSequencer  {
         // - no "skip the first use hints" is set, or
         // - "skip the first use hints" is set, but there is at least one account.
         boolean offerSignInOk = isSyncAllowed() && !isSignedIn() && !mForceEduSignIn
-                && (!shouldSkipFirstUseHints() || mGoogleAccounts.length > 0);
+                && (!shouldSkipFirstUseHints() || !mGoogleAccounts.isEmpty());
         freProperties.putBoolean(FirstRunActivity.SHOW_SIGNIN_PAGE, offerSignInOk);
         if (mForceEduSignIn || ChildAccountStatus.isChild(mChildAccountStatus)) {
             // If the device is an Android EDU device or has a child account, there should be
             // exactly account on the device. Force sign-in in to that account.
             freProperties.putString(
-                    AccountFirstRunFragment.FORCE_SIGNIN_ACCOUNT_TO, mGoogleAccounts[0].name);
+                    AccountFirstRunFragment.FORCE_SIGNIN_ACCOUNT_TO, mGoogleAccounts.get(0).name);
         }
 
         freProperties.putBoolean(

chrome/android/java/src/org/chromium/chrome/browser/firstrun/ForcedSigninProcessor.java

@@ -4,10 +4,8 @@
 
 package org.chromium.chrome.browser.firstrun;
 
-import android.accounts.Account;
 import android.content.Context;
 
-import org.chromium.base.Callback;
 import org.chromium.base.Log;
 import org.chromium.chrome.browser.ChromeActivity;
 import org.chromium.chrome.browser.externalauth.ExternalAuthUtils;
@@ -77,14 +75,12 @@ public final class ForcedSigninProcessor {
             Log.d(TAG, "Sign in disallowed");
             return;
         }
-        AccountManagerFacade.get().tryGetGoogleAccounts(new Callback<Account[]>() {
-            @Override
-            public void onResult(Account[] accounts) {
-                if (accounts.length != 1) {
-                    Log.d(TAG, "Incorrect number of accounts (%d)", accounts.length);
+        AccountManagerFacade.get().tryGetGoogleAccounts(accounts -> {
+            if (accounts.size() != 1) {
+                Log.d(TAG, "Incorrect number of accounts (%d)", accounts.size());
                 return;
             }
-                signinManager.signIn(accounts[0], null, new SigninManager.SignInCallback() {
+            signinManager.signIn(accounts.get(0), null, new SigninManager.SignInCallback() {
                 @Override
                 public void onSignInComplete() {
                     if (onComplete != null) {
@@ -99,7 +95,6 @@ public final class ForcedSigninProcessor {
                     }
                 }
             });
-            }
         });
     }
 

chrome/android/java/src/org/chromium/chrome/browser/omaha/RequestGenerator.java

@@ -201,7 +201,7 @@ public abstract class RequestGenerator {
                 () -> ProcessInitializationHandler.getInstance().initializePreNative());
         int numAccounts = 0;
         try {
-            numAccounts = AccountManagerFacade.get().getGoogleAccounts().length;
+            numAccounts = AccountManagerFacade.get().getGoogleAccounts().size();
         } catch (Exception e) {
             Log.e(TAG, "Can't get number of accounts.", e);
         }

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

@@ -15,6 +15,8 @@ import org.chromium.components.signin.AccountManagerFacade;
 import org.chromium.components.signin.ChromeSigninController;
 import org.chromium.components.sync.AndroidSyncSettings;
 
+import java.util.List;
+
 /**
  * A preference that displays the account currently being synced and allows the user to choose a new
  * account to use for syncing. The values used are the account names.
@@ -47,15 +49,15 @@ public class SyncedAccountPreference extends ListPreference {
             // signed in account
         }
 
-        Account[] accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
-        String[] accountNames = new String[accounts.length];
-        String[] accountValues = new String[accounts.length];
+        List<Account> accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
+        String[] accountNames = new String[accounts.size()];
+        String[] accountValues = new String[accounts.size()];
 
         String signedInAccountName = ChromeSigninController.get().getSignedInAccountName();
         String signedInSettingsKey = "";
 
-        for (int i = 0; i < accounts.length; ++i) {
-            Account account = accounts[i];
+        for (int i = 0; i < accounts.size(); ++i) {
+            Account account = accounts.get(i);
             accountNames[i] = account.name;
             accountValues[i] = account.name;
             boolean isPrimaryAccount = TextUtils.equals(account.name, signedInAccountName);

chrome/android/java/src/org/chromium/chrome/browser/signin/AccountManagementFragment.java

@@ -49,6 +49,8 @@ import org.chromium.chrome.browser.sync.ui.SyncCustomizationFragment;
 import org.chromium.components.signin.AccountManagerFacade;
 import org.chromium.components.signin.ChromeSigninController;
 
+import java.util.List;
+
 /**
  * The settings screen with information and settings related to the user's accounts.
  *
@@ -358,8 +360,9 @@ public class AccountManagementFragment extends PreferenceFragment
 
         accountsCategory.removeAll();
 
-        Account[] accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
-        for (final Account account : accounts) {
+        List<Account> accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
+        for (int i = 0; i < accounts.size(); i++) {
+            Account account = accounts.get(i);
             Preference pref = new Preference(getActivity());
             pref.setLayoutResource(R.layout.account_management_account_row);
             pref.setTitle(account.name);

chrome/android/java/src/org/chromium/chrome/browser/signin/AccountTrackerService.java

@@ -136,10 +136,11 @@ public class AccountTrackerService {
                 @Override
                 public String[][] doInBackground() {
                     Log.d(TAG, "Getting id/email mapping");
-                    String[][] accountIdNameMap = new String[2][accounts.length];
-                    for (int i = 0; i < accounts.length; ++i) {
-                        accountIdNameMap[0][i] = accountIdProvider.getAccountId(accounts[i].name);
-                        accountIdNameMap[1][i] = accounts[i].name;
+                    String[][] accountIdNameMap = new String[2][accounts.size()];
+                    for (int i = 0; i < accounts.size(); ++i) {
+                        accountIdNameMap[0][i] =
+                                accountIdProvider.getAccountId(accounts.get(i).name);
+                        accountIdNameMap[1][i] = accounts.get(i).name;
                     }
                     return accountIdNameMap;
                 }
@@ -222,9 +223,9 @@ public class AccountTrackerService {
                 return;
             }
 
-            String[] accountNames = new String[accounts.length];
-            for (int i = 0; i < accounts.length; ++i) {
-                accountNames[i] = accounts[i].name;
+            String[] accountNames = new String[accounts.size()];
+            for (int i = 0; i < accounts.size(); ++i) {
+                accountNames[i] = accounts.get(i).name;
             }
             if (nativeAreAccountsSeeded(accountNames)) {
                 mSystemAccountsSeedingStatus = SystemAccountsSeedingStatus.SEEDING_DONE;

chrome/android/java/src/org/chromium/chrome/browser/signin/SigninHelper.java

@@ -233,8 +233,9 @@ public class SigninHelper {
     }
 
     private static boolean accountExists(Account account) {
-        Account[] accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
-        for (Account a : accounts) {
+        List<Account> accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
+        for (int i = 0; i < accounts.size(); i++) {
+            Account a = accounts.get(i);
             if (a.equals(account)) {
                 return true;
             }

chrome/android/java/src/org/chromium/chrome/browser/signin/SigninPromoUtil.java

@@ -21,6 +21,7 @@ import org.chromium.components.signin.ChromeSigninController;
 import org.chromium.ui.base.WindowAndroid;
 
 import java.util.Collections;
+import java.util.List;
 import java.util.Set;
 
 /**
@@ -119,9 +120,9 @@ public class SigninPromoUtil {
             ProfileDataCache profileDataCache, PersonalizedSigninPromoView view,
             SigninPromoController.OnDismissListener listener) {
         DisplayableProfileData profileData = null;
-        Account[] accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
-        if (accounts.length > 0) {
-            String defaultAccountName = accounts[0].name;
+        List<Account> accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
+        if (accounts.size() > 0) {
+            String defaultAccountName = accounts.get(0).name;
             profileDataCache.update(Collections.singletonList(defaultAccountName));
             profileData = profileDataCache.getProfileDataOrDefault(defaultAccountName);
         }

chrome/android/java/src/org/chromium/chrome/browser/sync/ui/SyncCustomizationFragment.java

@@ -57,6 +57,7 @@ import org.chromium.components.sync.StopSource;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 /**
@@ -302,8 +303,8 @@ public class SyncCustomizationFragment extends PreferenceFragment
         // We remove the the SyncedAccountPreference if there's only 1 account on the device, so
         // it's possible for accountList to be null
         if (accountList != null) {
-            Account[] accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
-            if (accounts.length <= 1) {
+            List<Account> accounts = AccountManagerFacade.get().tryGetGoogleAccounts();
+            if (accounts.size() <= 1) {
                 getPreferenceScreen().removePreference(accountList);
             } else {
                 accountList.setEnabled(mSyncSwitchPreference.isChecked());

chrome/android/junit/src/org/chromium/chrome/browser/firstrun/FirstRunFlowSequencerTest.java

@@ -26,6 +26,9 @@ import org.chromium.base.test.BaseRobolectricTestRunner;
 import org.chromium.base.test.util.Feature;
 import org.chromium.components.signin.ChildAccountStatus;
 
+import java.util.Collections;
+import java.util.List;
+
 /**
  * Tests FirstRunFlowSequencer which contains the core logic of what should be shown during the
  * first run.
@@ -49,7 +52,7 @@ public class FirstRunFlowSequencerTest {
         public boolean isFirstRunFlowComplete;
         public boolean isSignedIn;
         public boolean isSyncAllowed;
-        public Account[] googleAccounts;
+        public List<Account> googleAccounts;
         public boolean hasAnyUserSeenToS;
         public boolean shouldSkipFirstUseHints;
         public boolean isFirstRunEulaAccepted;
@@ -83,7 +86,7 @@ public class FirstRunFlowSequencerTest {
         }
 
         @Override
-        public Account[] getGoogleAccounts() {
+        public List<Account> getGoogleAccounts() {
             return googleAccounts;
         }
 
@@ -140,12 +143,11 @@ public class FirstRunFlowSequencerTest {
     @Test
     @Feature({"FirstRun"})
     public void testFirstRunComplete() {
-        Account[] accounts = new Account[1];
-        accounts[0] = new Account(DEFAULT_ACCOUNT, GOOGLE_ACCOUNT_TYPE);
         mSequencer.isFirstRunFlowComplete = true;
         mSequencer.isSignedIn = false;
         mSequencer.isSyncAllowed = true;
-        mSequencer.googleAccounts = accounts;
+        mSequencer.googleAccounts =
+                Collections.singletonList(new Account(DEFAULT_ACCOUNT, GOOGLE_ACCOUNT_TYPE));
         mSequencer.hasAnyUserSeenToS = true;
         mSequencer.shouldSkipFirstUseHints = false;
         mSequencer.isFirstRunEulaAccepted = true;
@@ -164,7 +166,7 @@ public class FirstRunFlowSequencerTest {
         mSequencer.isFirstRunFlowComplete = false;
         mSequencer.isSignedIn = false;
         mSequencer.isSyncAllowed = true;
-        mSequencer.googleAccounts = new Account[0];
+        mSequencer.googleAccounts = Collections.emptyList();
         mSequencer.hasAnyUserSeenToS = false;
         mSequencer.shouldSkipFirstUseHints = false;
         mSequencer.shouldShowDataReductionPage = false;
@@ -189,12 +191,11 @@ public class FirstRunFlowSequencerTest {
     @Test
     @Feature({"FirstRun"})
     public void testStandardFlowOneChildAccount() {
-        Account[] accounts = new Account[1];
-        accounts[0] = new Account(DEFAULT_ACCOUNT, GOOGLE_ACCOUNT_TYPE);
         mSequencer.isFirstRunFlowComplete = false;
         mSequencer.isSignedIn = false;
         mSequencer.isSyncAllowed = true;
-        mSequencer.googleAccounts = accounts;
+        mSequencer.googleAccounts =
+                Collections.singletonList(new Account(DEFAULT_ACCOUNT, GOOGLE_ACCOUNT_TYPE));
         mSequencer.hasAnyUserSeenToS = false;
         mSequencer.shouldSkipFirstUseHints = false;
         mSequencer.shouldShowDataReductionPage = false;
@@ -224,7 +225,7 @@ public class FirstRunFlowSequencerTest {
         mSequencer.isFirstRunFlowComplete = false;
         mSequencer.isSignedIn = false;
         mSequencer.isSyncAllowed = true;
-        mSequencer.googleAccounts = new Account[0];
+        mSequencer.googleAccounts = Collections.emptyList();
         mSequencer.hasAnyUserSeenToS = false;
         mSequencer.shouldSkipFirstUseHints = false;
         mSequencer.shouldShowDataReductionPage = true;
@@ -253,7 +254,7 @@ public class FirstRunFlowSequencerTest {
         mSequencer.isFirstRunFlowComplete = false;
         mSequencer.isSignedIn = false;
         mSequencer.isSyncAllowed = true;
-        mSequencer.googleAccounts = new Account[0];
+        mSequencer.googleAccounts = Collections.emptyList();
         mSequencer.hasAnyUserSeenToS = false;
         mSequencer.shouldSkipFirstUseHints = false;
         mSequencer.shouldShowDataReductionPage = true;

components/signin/core/browser/android/java/src/org/chromium/components/signin/AccountManagerFacade.java

@@ -33,6 +33,8 @@ import org.chromium.components.signin.util.PatternMatcher;
 import org.chromium.net.NetworkChangeNotifier;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
 import java.util.concurrent.CountDownLatch;
@@ -83,9 +85,9 @@ public class AccountManagerFacade {
 
     // These two variables should be accessed from either UI thread or during initialization phase.
     private PatternMatcher[] mAccountRestrictionPatterns;
-    private AccountManagerResult<Account[]> mAllAccounts;
+    private AccountManagerResult<List<Account>> mAllAccounts;
 
-    private final AtomicReference<AccountManagerResult<Account[]>> mFilteredAccounts =
+    private final AtomicReference<AccountManagerResult<List<Account>>> mFilteredAccounts =
             new AtomicReference<>();
     private final CountDownLatch mPopulateAccountCacheLatch = new CountDownLatch(1);
     private final CachedMetrics.TimesHistogramSample mPopulateAccountCacheWaitingTimeHistogram =
@@ -270,7 +272,9 @@ public class AccountManagerFacade {
     @AnyThread
     public List<String> tryGetGoogleAccountNames() {
         List<String> accountNames = new ArrayList<>();
-        for (Account account : tryGetGoogleAccounts()) {
+        List<Account> tryGetGoogleAccounts = tryGetGoogleAccounts();
+        for (int i = 0; i < tryGetGoogleAccounts.size(); i++) {
+            Account account = tryGetGoogleAccounts.get(i);
             accountNames.add(account.name);
         }
         return accountNames;
@@ -291,10 +295,10 @@ public class AccountManagerFacade {
     public void getGoogleAccountNames(
             final Callback<AccountManagerResult<List<String>>> callback) {
         runAfterCacheIsPopulated(() -> {
-            final AccountManagerResult<Account[]> accounts = mFilteredAccounts.get();
+            final AccountManagerResult<List<Account>> accounts = mFilteredAccounts.get();
             final AccountManagerResult<List<String>> result;
             if (accounts.hasValue()) {
-                List<String> accountNames = new ArrayList<>(accounts.getValue().length);
+                List<String> accountNames = new ArrayList<>(accounts.getValue().size());
                 for (Account account : accounts.getValue()) {
                     accountNames.add(account.name);
                 }
@@ -313,8 +317,8 @@ public class AccountManagerFacade {
      *         Chrome lacks necessary permissions, etc.
      */
     @AnyThread
-    public Account[] getGoogleAccounts() throws AccountManagerDelegateException {
-        AccountManagerResult<Account[]> maybeAccounts = mFilteredAccounts.get();
+    public List<Account> getGoogleAccounts() throws AccountManagerDelegateException {
+        AccountManagerResult<List<Account>> maybeAccounts = mFilteredAccounts.get();
         if (maybeAccounts == null) {
             try {
                 // First call to update hasn't finished executing yet, should wait for it
@@ -336,7 +340,7 @@ public class AccountManagerFacade {
      * Asynchronous version of {@link #getGoogleAccounts()}.
      */
     @MainThread
-    public void getGoogleAccounts(final Callback<AccountManagerResult<Account[]>> callback) {
+    public void getGoogleAccounts(Callback<AccountManagerResult<List<Account>>> callback) {
         runAfterCacheIsPopulated(() -> callback.onResult(mFilteredAccounts.get()));
     }
 
@@ -345,11 +349,11 @@ public class AccountManagerFacade {
      * Returns an empty array if an error occurs while getting account list.
      */
     @AnyThread
-    public Account[] tryGetGoogleAccounts() {
+    public List<Account> tryGetGoogleAccounts() {
         try {
             return getGoogleAccounts();
         } catch (AccountManagerDelegateException e) {
-            return new Account[0];
+            return Collections.emptyList();
         }
     }
 
@@ -357,7 +361,7 @@ public class AccountManagerFacade {
      * Asynchronous version of {@link #tryGetGoogleAccounts()}.
      */
     @MainThread
-    public void tryGetGoogleAccounts(final Callback<Account[]> callback) {
+    public void tryGetGoogleAccounts(final Callback<List<Account>> callback) {
         runAfterCacheIsPopulated(() -> callback.onResult(tryGetGoogleAccounts()));
     }
 
@@ -367,7 +371,7 @@ public class AccountManagerFacade {
      */
     @AnyThread
     public boolean hasGoogleAccounts() {
-        return tryGetGoogleAccounts().length > 0;
+        return !tryGetGoogleAccounts().isEmpty();
     }
 
     /**
@@ -398,7 +402,7 @@ public class AccountManagerFacade {
     @AnyThread
     public Account getAccountFromName(String accountName) {
         String canonicalName = canonicalizeName(accountName);
-        Account[] accounts = tryGetGoogleAccounts();
+        List<Account> accounts = tryGetGoogleAccounts();
         for (Account account : accounts) {
             if (canonicalizeName(account.name).equals(canonicalName)) {
                 return account;
@@ -615,15 +619,16 @@ public class AccountManagerFacade {
         ContextUtils.getApplicationContext().registerReceiver(receiver, filter);
     }
 
-    private AccountManagerResult<Account[]> getAllAccounts() {
+    private AccountManagerResult<List<Account>> getAllAccounts() {
         try {
-            return new AccountManagerResult<>(mDelegate.getAccountsSync());
+            List<Account> accounts = Arrays.asList(mDelegate.getAccountsSync());
+            return new AccountManagerResult<>(Collections.unmodifiableList(accounts));
         } catch (AccountManagerDelegateException ex) {
             return new AccountManagerResult<>(ex);
         }
     }
 
-    private AccountManagerResult<Account[]> getFilteredAccounts() {
+    private AccountManagerResult<List<Account>> getFilteredAccounts() {
         if (mAllAccounts.hasException() || mAccountRestrictionPatterns == null) return mAllAccounts;
         ArrayList<Account> filteredAccounts = new ArrayList<>();
         for (Account account : mAllAccounts.getValue()) {
@@ -634,7 +639,7 @@ public class AccountManagerFacade {
                 }
             }
         }
-        return new AccountManagerResult<>(filteredAccounts.toArray(new Account[0]));
+        return new AccountManagerResult<>(Collections.unmodifiableList(filteredAccounts));
     }
 
     private static PatternMatcher[] getAccountRestrictionPatterns() {
@@ -673,7 +678,7 @@ public class AccountManagerFacade {
         fireOnAccountsChangedNotification();
     }
 
-    private void setAllAccounts(AccountManagerResult<Account[]> allAccounts) {
+    private void setAllAccounts(AccountManagerResult<List<Account>> allAccounts) {
         mAllAccounts = allAccounts;
         mFilteredAccounts.set(getFilteredAccounts());
         fireOnAccountsChangedNotification();
@@ -741,19 +746,19 @@ public class AccountManagerFacade {
         }
     }
 
-    private class UpdateAccountsTask extends AsyncTask<AccountManagerResult<Account[]>> {
+    private class UpdateAccountsTask extends AsyncTask<AccountManagerResult<List<Account>>> {
         @Override
         protected void onPreExecute() {
             ++mUpdateTasksCounter;
         }
 
         @Override
-        protected AccountManagerResult<Account[]> doInBackground() {
+        protected AccountManagerResult<List<Account>> doInBackground() {
             return getAllAccounts();
         }
 
         @Override
-        protected void onPostExecute(AccountManagerResult<Account[]> allAccounts) {
+        protected void onPostExecute(AccountManagerResult<List<Account>> allAccounts) {
             setAllAccounts(allAccounts);
             decrementUpdateCounter();
         }

components/signin/core/browser/android/junit/src/org/chromium/components/signin/test/AccountManagerFacadeRobolectricTest.java

@@ -14,6 +14,8 @@ import android.os.UserManager;
 import android.support.test.filters.SmallTest;
 import android.support.test.rule.UiThreadTestRule;
 
+import com.google.common.collect.ImmutableList;
+
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Rule;
@@ -22,7 +24,6 @@ import org.junit.runner.RunWith;
 import org.robolectric.RuntimeEnvironment;
 import org.robolectric.annotation.Config;
 
-import org.chromium.base.Callback;
 import org.chromium.base.task.test.CustomShadowAsyncTask;
 import org.chromium.base.test.BaseRobolectricTestRunner;
 import org.chromium.components.signin.AccountManagerDelegateException;
@@ -130,20 +131,20 @@ public class AccountManagerFacadeRobolectricTest {
     @Test
     @SmallTest
     public void testGetAccounts() throws AccountManagerDelegateException {
-        Assert.assertArrayEquals(new Account[] {}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(), mFacade.getGoogleAccounts());
 
         Account account = addTestAccount("test@gmail.com");
-        Assert.assertArrayEquals(new Account[] {account}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account), mFacade.getGoogleAccounts());
 
         Account account2 = addTestAccount("test2@gmail.com");
-        Assert.assertArrayEquals(new Account[] {account, account2}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account, account2), mFacade.getGoogleAccounts());
 
         Account account3 = addTestAccount("test3@gmail.com");
-        Assert.assertArrayEquals(
-                new Account[] {account, account2, account3}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(
+                ImmutableList.of(account, account2, account3), mFacade.getGoogleAccounts());
 
         removeTestAccount(account2);
-        Assert.assertArrayEquals(new Account[] {account, account3}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account, account3), mFacade.getGoogleAccounts());
     }
 
     @Test
@@ -151,19 +152,19 @@ public class AccountManagerFacadeRobolectricTest {
     public void testGetAccountsWithAccountPattern() throws AccountManagerDelegateException {
         setAccountRestrictionPatterns("*@example.com");
         Account account = addTestAccount("test@example.com");
-        Assert.assertArrayEquals(new Account[] {account}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account), mFacade.getGoogleAccounts());
 
         addTestAccount("test@gmail.com"); // Doesn't match the pattern.
-        Assert.assertArrayEquals(new Account[] {account}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account), mFacade.getGoogleAccounts());
 
         Account account2 = addTestAccount("test2@example.com");
-        Assert.assertArrayEquals(new Account[] {account, account2}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account, account2), mFacade.getGoogleAccounts());
 
         addTestAccount("test2@gmail.com"); // Doesn't match the pattern.
-        Assert.assertArrayEquals(new Account[] {account, account2}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account, account2), mFacade.getGoogleAccounts());
 
         removeTestAccount(account);
-        Assert.assertArrayEquals(new Account[] {account2}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account2), mFacade.getGoogleAccounts());
     }
 
     @Test
@@ -172,44 +173,44 @@ public class AccountManagerFacadeRobolectricTest {
         setAccountRestrictionPatterns("test1@example.com", "test2@gmail.com");
         addTestAccount("test@gmail.com"); // Doesn't match the pattern.
         addTestAccount("test@example.com"); // Doesn't match the pattern.
-        Assert.assertArrayEquals(new Account[] {}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(), mFacade.getGoogleAccounts());
 
         Account account = addTestAccount("test1@example.com");
-        Assert.assertArrayEquals(new Account[] {account}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account), mFacade.getGoogleAccounts());
 
         addTestAccount("test2@example.com"); // Doesn't match the pattern.
-        Assert.assertArrayEquals(new Account[] {account}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account), mFacade.getGoogleAccounts());
 
         Account account2 = addTestAccount("test2@gmail.com");
-        Assert.assertArrayEquals(new Account[] {account, account2}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account, account2), mFacade.getGoogleAccounts());
     }
 
     @Test
     @SmallTest
     public void testGetAccountsWithAccountPatternsChange() throws AccountManagerDelegateException {
-        Assert.assertArrayEquals(new Account[] {}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(), mFacade.getGoogleAccounts());
 
         Account account = addTestAccount("test@gmail.com");
-        Assert.assertArrayEquals(new Account[] {account}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account), mFacade.getGoogleAccounts());
 
         Account account2 = addTestAccount("test2@example.com");
-        Assert.assertArrayEquals(new Account[] {account, account2}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account, account2), mFacade.getGoogleAccounts());
 
         Account account3 = addTestAccount("test3@gmail.com");
-        Assert.assertArrayEquals(
-                new Account[] {account, account2, account3}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(
+                ImmutableList.of(account, account2, account3), mFacade.getGoogleAccounts());
 
         setAccountRestrictionPatterns("test@gmail.com");
-        Assert.assertArrayEquals(new Account[] {account}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account), mFacade.getGoogleAccounts());
 
         setAccountRestrictionPatterns("*@example.com", "test3@gmail.com");
-        Assert.assertArrayEquals(new Account[] {account2, account3}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account2, account3), mFacade.getGoogleAccounts());
 
         removeTestAccount(account3);
-        Assert.assertArrayEquals(new Account[] {account2}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account2), mFacade.getGoogleAccounts());
 
         clearAccountRestrictionPatterns();
-        Assert.assertArrayEquals(new Account[] {account, account2}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account, account2), mFacade.getGoogleAccounts());
     }
 
     @Test
@@ -217,7 +218,7 @@ public class AccountManagerFacadeRobolectricTest {
     public void testGetAccountsMultipleMatchingPatterns() throws AccountManagerDelegateException {
         setAccountRestrictionPatterns("*@gmail.com", "test@gmail.com");
         Account account = addTestAccount("test@gmail.com"); // Matches both patterns
-        Assert.assertArrayEquals(new Account[] {account}, mFacade.getGoogleAccounts());
+        Assert.assertEquals(ImmutableList.of(account), mFacade.getGoogleAccounts());
     }
 
     @Test
@@ -256,12 +257,9 @@ public class AccountManagerFacadeRobolectricTest {
     private void assertChildAccountStatus(
             Account account, @ChildAccountStatus.Status Integer status) {
         final AtomicInteger callCount = new AtomicInteger();
-        AccountManagerFacade.get().checkChildAccountStatus(account, new Callback<Integer>() {
-            @Override
-            public void onResult(@ChildAccountStatus.Status Integer result) {
+        AccountManagerFacade.get().checkChildAccountStatus(account, result -> {
             callCount.incrementAndGet();
             Assert.assertEquals(result, status);
-            }
         });
         Assert.assertEquals(1, callCount.get());
     }

components/sync/android/java/src/org/chromium/components/sync/AndroidSyncSettings.java

@@ -14,6 +14,7 @@ import android.os.StrictMode;
 import org.chromium.base.Callback;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.ObserverList;
+import org.chromium.base.StrictModeContext;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.components.signin.AccountManagerFacade;
@@ -242,7 +243,7 @@ public class AndroidSyncSettings {
 
         mIsSyncable = shouldBeSyncable;
 
-        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
+        try (StrictModeContext ignored = StrictModeContext.allowDiskWrites()) {
             // Make account syncable if there is one.
             if (shouldBeSyncable) {
                 mSyncContentResolverDelegate.setIsSyncable(mAccount, mContractAuthority, 1);
@@ -250,18 +251,15 @@ public class AndroidSyncSettings {
                 mSyncContentResolverDelegate.removePeriodicSync(
                         mAccount, mContractAuthority, Bundle.EMPTY);
             }
-        StrictMode.setThreadPolicy(oldPolicy);
+        }
 
         // Disable the syncability of Chrome for all other accounts.
-        ThreadUtils.postOnUiThread(new Runnable() {
-            @Override
-            public void run() {
-                AccountManagerFacade.get().tryGetGoogleAccounts(new Callback<Account[]>() {
-                    @Override
-                    public void onResult(Account[] accounts) {
+        ThreadUtils.postOnUiThread(() -> {
+            AccountManagerFacade.get().tryGetGoogleAccounts(accounts -> {
                 synchronized (mLock) {
-                            StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
-                            for (Account account : accounts) {
+                    try (StrictModeContext ignored = StrictModeContext.allowDiskWrites()) {
+                        for (int i = 0; i < accounts.size(); i++) {
+                            Account account = accounts.get(i);
                             if (!account.equals(mAccount)
                                     && mSyncContentResolverDelegate.getIsSyncable(
                                                account, mContractAuthority)
@@ -270,13 +268,11 @@ public class AndroidSyncSettings {
                                         account, mContractAuthority, 0);
                             }
                         }
-                            StrictMode.setThreadPolicy(oldPolicy);
+                    }
                 }
 
                 if (callback != null) callback.onResult(true);
-                    }
             });
-            }
         });
     }