<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Bridge\Doctrine;

use Symfony\Component\DependencyInjection\ContainerAwareInterface;
use Symfony\Component\DependencyInjection\ContainerAwareTrait;
use Doctrine\Common\Persistence\AbstractManagerRegistry;

/**
 * References Doctrine connections and entity/document managers.
 *
 * @author  Lukas Kahwe Smith <smith@pooteeweet.org>
 */
abstract class ManagerRegistry extends AbstractManagerRegistry implements ContainerAwareInterface
{
    use ContainerAwareTrait;

    /**
     * {@inheritdoc}
     */
    protected function getService($name)
    {
        return $this->container->get($name);
    }

    /**
     * {@inheritdoc}
     */
    protected function resetService($name)
    {
        $this->container->set($name, null);
    }
}

<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Bridge\Doctrine;

use Symfony\Component\DependencyInjection\ContainerAwareInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Doctrine\Common\Persistence\AbstractManagerRegistry;

/**
 * References Doctrine connections and entity/document managers.
 *
 * @author  Lukas Kahwe Smith <smith@pooteeweet.org>
 */
abstract class ManagerRegistry extends AbstractManagerRegistry implements ContainerAwareInterface
{
    /**
     * @var ContainerInterface
     */
    protected $container;

    /**
     * {@inheritdoc}
     */
    protected function getService($name)
    {
        return $this->container->get($name);
    }

    /**
     * {@inheritdoc}
     */
    protected function resetService($name)
    {
        $this->container->set($name, null);
    }

    /**
     * {@inheritdoc}
     */
    public function setContainer(ContainerInterface $container = null)
    {
        $this->container = $container;
    }
}

--- 
+++ 
@@ -12,7 +12,7 @@
 namespace Symfony\Bridge\Doctrine;
 
 use Symfony\Component\DependencyInjection\ContainerAwareInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\DependencyInjection\ContainerAwareTrait;
 use Doctrine\Common\Persistence\AbstractManagerRegistry;
 
 /**
@@ -22,10 +22,7 @@
  */
 abstract class ManagerRegistry extends AbstractManagerRegistry implements ContainerAwareInterface
 {
-    /**
-     * @var ContainerInterface
-     */
-    protected $container;
+    use ContainerAwareTrait;
 
     /**
      * {@inheritdoc}
@@ -42,12 +39,4 @@
     {
         $this->container->set($name, null);
     }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function setContainer(ContainerInterface $container = null)
-    {
-        $this->container = $container;
-    }
 }
Remove deprecated ContainerAware class and make use of the trait in another class

