[Signin][Android] Migrate SigninManager.isSignInAllowed to use IdentityManager

Replace ChromeSigninController in SigninManager.isSignInAllowed with
IdentityManager.GetPrimaryAccountInfo(). This is safe to do, because
the native side is already loaded if SigninManager exists.

Bug: 1058981
Change-Id: I34d469463fe6d5f03ba8ce02a9efd326474b7ab9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2089763Reviewed-by: Alice Wang <aliceywang@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#757046}

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

@@ -285,7 +285,7 @@ public class SigninManager
      */
     public boolean isSignInAllowed() {
         return !mFirstRunCheckIsPending && mSignInState == null && mSigninAllowedByPolicy
-                && ChromeSigninController.get().getSignedInUser() == null && isSigninSupported();
+                && mIdentityManager.getPrimaryAccountInfo() == null && isSigninSupported();
     }
 
     /**

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

@@ -26,6 +26,7 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
+import org.mockito.stubbing.Answer;
 import org.robolectric.annotation.Config;
 
 import org.chromium.base.test.BaseRobolectricTestRunner;
@@ -242,10 +243,13 @@ public class SigninManagerTest {
         doReturn(account)
                 .when(mIdentityManager)
                 .findExtendedAccountInfoForAccountWithRefreshTokenByEmailAddress(any());
-        // TODO(https://crbug.com/1054780): Mock getPrimaryAccountInfo instead.
-        doReturn(false).when(mIdentityManager).hasPrimaryAccount();
-        doReturn(true).when(mIdentityMutator).setPrimaryAccount(any());
-        doReturn(account).when(mIdentityManager).getPrimaryAccountInfo();
+        doReturn(null).when(mIdentityManager).getPrimaryAccountInfo();
+        Answer<Boolean> setPrimaryAccountAnswer = invocation -> {
+            // From now on getPrimaryAccountInfo should return account.
+            doReturn(account).when(mIdentityManager).getPrimaryAccountInfo();
+            return true;
+        };
+        doAnswer(setPrimaryAccountAnswer).when(mIdentityMutator).setPrimaryAccount(account.getId());
         doNothing().when(mIdentityMutator).reloadAllAccountsFromSystemWithPrimaryAccount(any());
 
         mSigninManager.onFirstRunCheckDone(); // Allow sign-in.