Migrate excluded account ids from profile OAuth2 token service.

This CL only concerns iOS. It migrates the excluded accounts from
emails to account ids if the account tracker migration is in progress.

BUG=522454

Review URL: https://codereview.chromium.org/1303843002

Cr-Commit-Position: refs/heads/master@{#344476}

2 files changed, 53 insertions, 0 deletions

diff --git a/components/signin/ios/browser/profile_oauth2_token_service_ios_delegate.h b/components/signin/ios/browser/profile_oauth2_token_service_ios_delegate.h
index 1083f03..c278986 100644
--- a/components/signin/ios/browser/profile_oauth2_token_service_ios_delegate.h
+++ b/components/signin/ios/browser/profile_oauth2_token_service_ios_delegate.h
@@ -123,6 +123,9 @@ class ProfileOAuth2TokenServiceIOSDelegate : public OAuth2TokenServiceDelegate {
                          const std::string& email,
                          const std::set<std::string>& excluded_account_ids);
 
+  // Migrates the excluded secondary accounts from emails to account ids.
+  void MigrateExcludedSecondaryAccountIds();
+
   // The primary account id.
   std::string primary_account_id_;
 
diff --git a/components/signin/ios/browser/profile_oauth2_token_service_ios_delegate.mm b/components/signin/ios/browser/profile_oauth2_token_service_ios_delegate.mm
index 1c48708..527bcc2 100644
--- a/components/signin/ios/browser/profile_oauth2_token_service_ios_delegate.mm
+++ b/components/signin/ios/browser/profile_oauth2_token_service_ios_delegate.mm
@@ -199,6 +199,10 @@ void ProfileOAuth2TokenServiceIOSDelegate::Shutdown() {
 void ProfileOAuth2TokenServiceIOSDelegate::LoadCredentials(
     const std::string& primary_account_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  if (account_tracker_service_->GetMigrationState() ==
+      AccountTrackerService::MIGRATION_IN_PROGRESS) {
+    MigrateExcludedSecondaryAccountIds();
+  }
 
   // LoadCredentials() is called iff the user is signed in to Chrome, so the
   // primary account id must not be empty.
@@ -487,3 +491,49 @@ bool ProfileOAuth2TokenServiceIOSDelegate::IsAccountExcluded(
     return true;
   return excluded_account_ids.count(account_id) > 0;
 }
+
+void ProfileOAuth2TokenServiceIOSDelegate::
+    MigrateExcludedSecondaryAccountIds() {
+  DCHECK_EQ(AccountTrackerService::MIGRATION_IN_PROGRESS,
+            account_tracker_service_->GetMigrationState());
+
+  // Before the account id migration, emails were used as account identifiers.
+  // Thus the pref |prefs::kTokenServiceExcludedSecondaryAccounts| holds the
+  // emails of the excluded secondary accounts.
+  std::set<std::string> excluded_emails = GetExcludedSecondaryAccounts();
+  if (excluded_emails.empty())
+    return;
+
+  std::vector<std::string> excluded_account_ids;
+  for (const std::string& excluded_email : excluded_emails) {
+    ProfileOAuth2TokenServiceIOSProvider::AccountInfo account_info =
+        provider_->GetAccountInfoForEmail(excluded_email);
+    if (account_info.gaia.empty()) {
+      // The provider no longer has an account with email |excluded_email|.
+      // This can occur for 2 reasons:
+      // 1. The account with email |excluded_email| was removed before being
+      //   migrated. It may simply be ignored in this case (no need to exclude
+      //   an account that is no longer available).
+      // 2. The migration of the excluded account ids was already done before,
+      //   but the entire migration of the accounts did not end for whatever
+      //   reason (e.g. the app crashed during the previous attempt to migrate
+      //   the accounts). The entire migration should be ignored in this case.
+      if (provider_->GetAccountInfoForGaia(excluded_email).gaia.empty()) {
+        // Case 1 above (account was removed).
+        DVLOG(1) << "Excluded secondary account with email " << excluded_email
+                 << " was removed before migration.";
+      } else {
+        // Case 2 above (migration already done).
+        DVLOG(1) << "Excluded secondary account ids were already migrated.";
+        return;
+      }
+    } else {
+      std::string excluded_account_id =
+          account_tracker_service_->PickAccountIdForAccount(account_info.gaia,
+                                                            account_info.email);
+      excluded_account_ids.push_back(excluded_account_id);
+    }
+  }
+  ClearExcludedSecondaryAccounts();
+  ExcludeSecondaryAccounts(excluded_account_ids);
+}