[Signin][Android] Filter account list when child account is present

This CL implements account list filtering when there are multiple
accounts on the device and one of these accounts is a child account.
In this case AccountManagerFacade will expose the child account only.

Bug: 779568
Change-Id: I70fb00fc692e3f54c779ac618167afd9ad728c09
Reviewed-on: https://chromium-review.googlesource.com/819414Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523524}

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

@@ -571,7 +571,19 @@ public class AccountManagerFacade {
 
         private AccountManagerResult<Account[]> getAccountManagerResult() {
             try {
-                return new AccountManagerResult<>(mDelegate.getAccountsSync());
+                Account[] accounts = mDelegate.getAccountsSync();
+                if (accounts.length <= 1) return new AccountManagerResult<>(accounts);
+
+                ArrayList<Account> filteredAccounts = new ArrayList<>();
+                for (Account account : accounts) {
+                    if (hasFeatures(account, new String[] {FEATURE_IS_CHILD_ACCOUNT_KEY})) {
+                        filteredAccounts.add(account);
+                    }
+                }
+                // Don't filter if there are no child accounts
+                if (filteredAccounts.isEmpty()) return new AccountManagerResult<>(accounts);
+
+                return new AccountManagerResult<>(filteredAccounts.toArray(new Account[0]));
             } catch (AccountManagerDelegateException ex) {
                 return new AccountManagerResult<>(ex);
             }

components/signin/core/browser/android/javatests/src/org/chromium/components/signin/test/AccountManagerFacadeTest.java

@@ -5,6 +5,7 @@
 package org.chromium.components.signin.test;
 
 import android.accounts.Account;
+import android.support.test.filters.MediumTest;
 import android.support.test.filters.SmallTest;
 import android.support.test.rule.UiThreadTestRule;
 
@@ -15,6 +16,7 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 
 import org.chromium.base.test.BaseJUnit4ClassRunner;
+import org.chromium.components.signin.AccountManagerDelegateException;
 import org.chromium.components.signin.AccountManagerFacade;
 import org.chromium.components.signin.ProfileDataSource;
 import org.chromium.components.signin.test.util.AccountHolder;
@@ -64,6 +66,42 @@ public class AccountManagerFacadeTest {
         Assert.assertTrue(mFacade.hasAccountForName("te.st.me@gmail.com"));
     }
 
+    @Test
+    @MediumTest
+    public void testGetAccountsMultipleAccounts() throws AccountManagerDelegateException {
+        Assert.assertArrayEquals(new Account[] {}, mFacade.getGoogleAccounts());
+
+        Account account = addTestAccount("test@gmail.com");
+        Assert.assertArrayEquals(new Account[] {account}, mFacade.getGoogleAccounts());
+
+        Account account2 = addTestAccount("test2@gmail.com");
+        Assert.assertArrayEquals(new Account[] {account, account2}, mFacade.getGoogleAccounts());
+
+        Account account3 = addTestAccount("test3@gmail.com");
+        Assert.assertArrayEquals(
+                new Account[] {account, account2, account3}, mFacade.getGoogleAccounts());
+
+        removeTestAccount(account2);
+        Assert.assertArrayEquals(new Account[] {account, account3}, mFacade.getGoogleAccounts());
+    }
+
+    @Test
+    @MediumTest
+    public void testGetAccountsChildAccountFiltering() throws AccountManagerDelegateException {
+        Account account = addTestAccount("test@gmail.com");
+        Assert.assertArrayEquals(new Account[] {account}, mFacade.getGoogleAccounts());
+
+        Account childAccount = addChildTestAccount("child@gmail.com");
+        Assert.assertArrayEquals(new Account[] {childAccount}, mFacade.getGoogleAccounts());
+
+        Account account2 = addTestAccount("test2@gmail.com");
+        Assert.assertArrayEquals(new Account[] {childAccount}, mFacade.getGoogleAccounts());
+
+        // If child account is gone, non-child accounts should be exposed again
+        removeTestAccount(childAccount);
+        Assert.assertArrayEquals(new Account[] {account, account2}, mFacade.getGoogleAccounts());
+    }
+
     @Test
     @SmallTest
     public void testProfileDataSource() throws Throwable {
@@ -92,4 +130,19 @@ public class AccountManagerFacadeTest {
         mDelegate.addAccountHolderBlocking(holder);
         return account;
     }
+
+    private Account addChildTestAccount(String accountName) {
+        Account account = AccountManagerFacade.createAccountFromName(accountName);
+        AccountHolder holder =
+                AccountHolder.builder(account)
+                        .alwaysAccept(true)
+                        .addFeature(AccountManagerFacade.FEATURE_IS_CHILD_ACCOUNT_KEY)
+                        .build();
+        mDelegate.addAccountHolderBlocking(holder);
+        return account;
+    }
+
+    private void removeTestAccount(Account account) {
+        mDelegate.removeAccountHolderBlocking(AccountHolder.builder(account).build());
+    }
 }

components/signin/core/browser/android/javatests/src/org/chromium/components/signin/test/util/FakeAccountManagerDelegate.java

@@ -29,7 +29,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
 import java.util.UUID;
@@ -112,7 +112,7 @@ public class FakeAccountManagerDelegate implements AccountManagerDelegate {
     /** Use {@link FakeProfileDataSource}. */
     public static final int ENABLE_PROFILE_DATA_SOURCE = 1;
 
-    private final Set<AccountHolder> mAccounts = new HashSet<>();
+    private final Set<AccountHolder> mAccounts = new LinkedHashSet<>();
     private final ObserverList<AccountsChangeObserver> mObservers = new ObserverList<>();
     private boolean mRegisterObserversCalled;
     private FakeProfileDataSource mFakeProfileDataSource;