Constructs a PerformanceForm object.
\Drupal\Core\Config\ConfigFactory $config_factory: The factory for configuration objects.
\Drupal\Core\Config\Context\ContextInterface $context: The configuration context used for this configuration object.
\Drupal\Core\Cache\CacheBackendInterface $page_cache:
Overrides SystemConfigFormBase::__construct
public function __construct(ConfigFactory $config_factory, ContextInterface $context, CacheBackendInterface $page_cache) {
parent::__construct($config_factory, $context);
$this->pageCache = $page_cache;
}