Fix IdentityManager::HasPrimaryAccount()

"Signing out" always happens via SigninManager and causes the account to
be removed from SigninManager as well as AccountTrackerService. However,
the primary account can be removed from AccountTrackerService in
circumstances *other than* the user signing out of the primary account;
e.g., if the refresh token for the account is revoked from
ProfileOAuth2TokenService. In these circumstances, there would still be
a primary account (i.e., SigninManagerBase::GetAuthenticatedAccountId()
returns a valid account ID), but there would be no AccountInfo for the
account (i.e., SigninManagerBase::GetAuthenticatedAccountInfo() returns
an empty AccountInfo).

IdentityManager::HasPrimaryAccount() currently internally uses
SigninManagerBase::GetAuthenticatedAccountInfo(). This will result in it
giving an incorrect result in these edge cases. This CL changes it to
use SigninManagerBase::IsAuthenticated() and adds a test that fails
before the change.

Bug: 892553
Change-Id: I227ad6767089b259c0d54e33f5f88f6789f2de9a
Reviewed-on: https://chromium-review.googlesource.com/c/1264203Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#597064}

services/identity/public/cpp/identity_manager.cc

@@ -69,7 +69,7 @@ AccountInfo IdentityManager::GetPrimaryAccountInfo() const {
 }
 
 bool IdentityManager::HasPrimaryAccount() const {
-  return !GetPrimaryAccountInfo().account_id.empty();
+  return signin_manager_->IsAuthenticated();
 }
 
 #if !defined(OS_CHROMEOS)

services/identity/public/cpp/identity_manager_unittest.cc

@@ -750,7 +750,15 @@ TEST_F(IdentityManagerTest, PrimaryAccountInfoAfterSigninAndSignout) {
 TEST_F(IdentityManagerTest, HasPrimaryAccount) {
   EXPECT_TRUE(identity_manager()->HasPrimaryAccount());
 
+  // Removing the account from the AccountTrackerService should not cause
+  // IdentityManager to think that there is no longer a primary account.
+  account_tracker()->RemoveAccount(
+      identity_manager()->GetPrimaryAccountInfo().account_id);
+  EXPECT_TRUE(identity_manager()->HasPrimaryAccount());
+
 #if !defined(OS_CHROMEOS)
+  // Signing out should cause IdentityManager to recognize that there is no
+  // longer a primary account.
   base::RunLoop run_loop;
   identity_manager_observer()->set_on_primary_account_cleared_callback(
       run_loop.QuitClosure());