Prefer to use the AccountID to the Email from ListAccounts.

components/signin/core/browser/gaia_cookie_manager_service.cc

Index: components/signin/core/browser/gaia_cookie_manager_service.cc
diff --git a/components/signin/core/browser/gaia_cookie_manager_service.cc b/components/signin/core/browser/gaia_cookie_manager_service.cc
index 4db5fa6ecb4e4f0b7af77fc87fe25edc176e4e34..4beff36cbccc78951d073ada993e79b2978602a5 100644
--- a/components/signin/core/browser/gaia_cookie_manager_service.cc
+++ b/components/signin/core/browser/gaia_cookie_manager_service.cc
@@ -561,7 +561,8 @@ void GaiaCookieManagerService::OnListAccountsSuccess(const std::string& data) {
     return;
   }
 
-  for (gaia::ListedAccount account : listed_accounts_) {
+  for (gaia::ListedAccount& account : listed_accounts_) {
+    DCHECK(account.id.empty());
     account.id = AccountTrackerService::PickAccountIdForAccount(
         signin_client_->GetPrefs(), account.gaia_id, account.email);
   }