[HttpKernel] Fix missing use statement in RegisterControllerArgumentLocatorsPass

Author: chalasr

src/Symfony/Component/HttpKernel/DependencyInjection/RegisterControllerArgumentLocatorsPass.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\HttpKernel\DependencyInjection;
 
+use Symfony\Component\DependencyInjection\ChildDefinition;
 use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
 use Symfony\Component\DependencyInjection\Compiler\ServiceLocatorTagPass;
 use Symfony\Component\DependencyInjection\ContainerBuilder;