[IdentityManager] Add DCHECK to make error case less cryptic in tests

When tests set the refresh token for a given account, IdentityManager
must already know about the account (i.e., the account must be
seeded in AccountTrackerService). However, the error that occurs if
tests invoke SetRefreshTokenForAccount() rather than
MakeAccountAvailable() is cryptic and hard to debug. This CL adds a
DCHECK to make the error more transparent and give instructions on the
proper invocation.

Change-Id: I26e38bbccfd16e3e9b0e5c45931edb26ea0e4f0d
Bug: 798699
Reviewed-on: https://chromium-review.googlesource.com/c/1350610Reviewed-by: Antonio Gomes <tonikitoo@igalia.com>
Commit-Queue: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610832}

services/identity/public/cpp/identity_test_utils.cc

@@ -114,10 +114,16 @@ void OneShotIdentityManagerObserver::OnAccountsInCookieUpdated(
 
 // Helper function that updates the refresh token for |account_id| to
 // |new_token|. Blocks until the update is processed by |identity_manager|.
-void UpdateRefreshTokenForAccount(ProfileOAuth2TokenService* token_service,
-                                  IdentityManager* identity_manager,
-                                  const std::string& account_id,
-                                  const std::string& new_token) {
+void UpdateRefreshTokenForAccount(
+    ProfileOAuth2TokenService* token_service,
+    AccountTrackerService* account_tracker_service,
+    IdentityManager* identity_manager,
+    const std::string& account_id,
+    const std::string& new_token) {
+  DCHECK_EQ(account_tracker_service->GetAccountInfo(account_id).account_id,
+            account_id)
+      << "To set the refresh token for an unknown account, use "
+         "MakeAccountAvailable()";
   base::RunLoop run_loop;
   OneShotIdentityManagerObserver token_updated_observer(
       identity_manager, run_loop.QuitClosure(),
@@ -272,14 +278,17 @@ void SetRefreshTokenForAccount(IdentityManager* identity_manager,
                                const std::string& account_id) {
   std::string refresh_token = "refresh_token_for_" + account_id;
   UpdateRefreshTokenForAccount(identity_manager->GetTokenService(),
+                               identity_manager->GetAccountTrackerService(),
                                identity_manager, account_id, refresh_token);
 }
 
 void SetInvalidRefreshTokenForAccount(IdentityManager* identity_manager,
                                       const std::string& account_id) {
   UpdateRefreshTokenForAccount(
-      identity_manager->GetTokenService(), identity_manager, account_id,
-      OAuth2TokenServiceDelegate::kInvalidRefreshToken);
+      identity_manager->GetTokenService(),
+
+      identity_manager->GetAccountTrackerService(), identity_manager,
+      account_id, OAuth2TokenServiceDelegate::kInvalidRefreshToken);
 }
 
 void RemoveRefreshTokenForAccount(IdentityManager* identity_manager,