CM API: disallow a federated credential to update a password credential.

components/password_manager/core/browser/password_form_manager.cc

Index: components/password_manager/core/browser/password_form_manager.cc
diff --git a/components/password_manager/core/browser/password_form_manager.cc b/components/password_manager/core/browser/password_form_manager.cc
index 59d9c0a91bb89e33c4be5db936ee225af993359d..919f1713356e03910906a138c9b80744fe276484 100644
--- a/components/password_manager/core/browser/password_form_manager.cc
+++ b/components/password_manager/core/browser/password_form_manager.cc
@@ -1218,6 +1218,8 @@ const PasswordForm* PasswordFormManager::FindBestMatchForUpdatePassword(
 
 const PasswordForm* PasswordFormManager::FindBestSavedMatch(
     const PasswordForm* form) const {
+  if (!form->federation_origin.unique())
+    return nullptr;
   auto it = best_matches_.find(form->username_value);
   if (it != best_matches_.end())
     return it->second;