There's now a dedicated nsIQuotaManagerService::ClearStoragesForOriginPrefix method for clearing storages for origin prefix. All callers of nsIQuotaManagerService::ClearStoragesForPrincipal which want to clear all storages for given origin prefix can be now converted to call the new method. Changed done in this patch: - replaced some nsIQuotaManagerService::ClearStoragesForPrincipal calls with nsIQuotaManagerService::ClearStoragesForOriginPrefix Differential Revision: https://phabricator.services.mozilla.com/D186778