Use PrimaryAccountMutator in SigninManagerAndroid

Use the public API of IdentityManager, PrimaryAccountMutator, to set the
primary account instead of using IdentityManager's internals
(PrimaryAccountManager).

PrimaryAccountMutatorImpl::SetPrimaryAccount calls PrimaryAccountManager::Signin, with added pre-conditions:
  - Preferences allow the signin
  - There is no primary account already set (IsAuthenticated)
  - AccountTrackerService knows about the account, and it has both a
    valid account_id and email.
If those are not met, SetPrimaryAccount does not call PrimaryAccountManager::SignIn and returns false.

In practice, those are already met or were already required:
  - Most of SignIn calls do check the preferences beforehand. Two
    exceptions: Re-authentication cases (SyncAndServicesPreferences, SignInHelper), SigninFragment.
  - PrimaryAccountManager::Signin and
    PrimaryAccountManager::SetAuthenticatedAccountId also verify that.
    If the user is authenticated, the signin is not completed, no
    notifications are sent. A slight behavior change could happen here
    though: a DCHECK verifies that the same user is re-authenticating.
  - PrimaryAccountManager::SignIn also needs AccountTrackerService to be
    properly initialized with the account.

Bug: 987965
Change-Id: I70f30bcf3536a79bb5983333233c59aeb5b8a5a1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1738696
Commit-Queue: Pâris Meuleman <pmeuleman@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Auto-Submit: Pâris Meuleman <pmeuleman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#685149}

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

@@ -464,7 +464,7 @@ public class SigninManager implements AccountTrackerService.OnSystemAccountsSeed
         // This method should be called at most once per sign-in flow.
         assert mSignInState != null;
 
-        SigninManagerJni.get().onSignInCompleted(
+        SigninManagerJni.get().setPrimaryAccount(
                 mNativeSigninManagerAndroid, mSignInState.mAccount.name);
 
         // Cache the signed-in account name. This must be done after the native call, otherwise
@@ -744,7 +744,7 @@ public class SigninManager implements AccountTrackerService.OnSystemAccountsSeed
 
         boolean isForceSigninEnabled(long nativeSigninManagerAndroid);
 
-        void onSignInCompleted(long nativeSigninManagerAndroid, String username);
+        void setPrimaryAccount(long nativeSigninManagerAndroid, String username);
 
         void signOut(long nativeSigninManagerAndroid, @SignoutReason int reason);
 

chrome/android/junit/src/org/chromium/chrome/browser/signin/SigninManagerTest.java

@@ -219,7 +219,7 @@ public class SigninManagerTest {
         doNothing().when(mNativeMock).fetchAndApplyCloudPolicy(anyLong(), any(), any());
 
         doReturn(true).when(mSigninManager).isSigninSupported();
-        doNothing().when(mNativeMock).onSignInCompleted(anyLong(), any());
+        doNothing().when(mNativeMock).setPrimaryAccount(anyLong(), any());
         doNothing().when(mSigninManager).logInSignedInUser();
 
         mSigninManager.onFirstRunCheckDone(); // Allow sign-in.

chrome/browser/android/signin/signin_manager_android.cc

@@ -162,16 +162,19 @@ void SigninManagerAndroid::Shutdown() {
                              java_signin_manager_);
 }
 
-void SigninManagerAndroid::OnSignInCompleted(
+void SigninManagerAndroid::SetPrimaryAccount(
     JNIEnv* env,
     const JavaParamRef<jstring>& username) {
-  DVLOG(1) << "SigninManagerAndroid::OnSignInCompleted";
+  DVLOG(1) << "SigninManagerAndroid::SetPrimaryAccount";
 
-  // TODO(crbug.com/987965): Migrate away from this direct usage of
-  // PrimaryAccountManager and eliminate this class needing to know about
-  // PrimaryAccountManager.
-  identity_manager_->GetPrimaryAccountManager()->SignIn(
-      base::android::ConvertJavaStringToUTF8(env, username));
+  auto account =
+      identity_manager_
+          ->FindExtendedAccountInfoForAccountWithRefreshTokenByEmailAddress(
+              base::android::ConvertJavaStringToUTF8(env, username));
+  DCHECK(account.has_value());
+  auto* account_mutator = identity_manager_->GetPrimaryAccountMutator();
+  bool result = account_mutator->SetPrimaryAccount(account->account_id);
+  CHECK(result);
 }
 
 void SigninManagerAndroid::SignOut(JNIEnv* env,

chrome/browser/android/signin/signin_manager_android.h

@@ -44,7 +44,7 @@ class SigninManagerAndroid : public KeyedService,
 
   // Indicates that the user has made the choice to sign-in. |username|
   // contains the email address of the account to use as primary.
-  void OnSignInCompleted(JNIEnv* env,
+  void SetPrimaryAccount(JNIEnv* env,
                          const base::android::JavaParamRef<jstring>& username);
 
   void SignOut(JNIEnv* env,

components/signin/public/identity_manager/identity_manager.h

@@ -33,9 +33,7 @@ class SharedURLLoaderFactory;
 class TestURLLoaderFactory;
 }  // namespace network
 
-// Necessary to declare these classes as friends.
 class PrefRegistrySimple;
-class SigninManagerAndroid;
 
 class AccountFetcherService;
 class AccountTrackerService;
@@ -537,10 +535,6 @@ class IdentityManager : public KeyedService,
       const std::string& locale,
       const std::string& picture_url);
 
-  // These friends are temporary during the conversion process.
-  // TODO(https://crbug.com/889902): Delete this when conversion is done.
-  friend SigninManagerAndroid;
-
   // Temporary access to getters (e.g. GetTokenService()).
   // TODO(https://crbug.com/944127): Remove this friendship by
   // extending identity_test_utils.h as needed.