Issue #2303703 by dawehner: Remove unused RegisterParamConvertersPass.

core/lib/Drupal/Core/DependencyInjection/Compiler/RegisterParamConvertersPass.php

-<?php
-
-/**
- * @file
- * Contains Drupal\Core\DependencyInjection\Compiler\RegisterParamConvertersPass.
- */
-
-namespace Drupal\Core\DependencyInjection\Compiler;
-
-use Symfony\Component\DependencyInjection\ContainerBuilder;
-use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
-use Symfony\Component\DependencyInjection\Reference;
-
-/**
- * Registers EntityConverter services with the ParamConverterManager.
- */
-class RegisterParamConvertersPass implements CompilerPassInterface {
-
-  /**
-   * Adds services tagged with "paramconverter" to the param converter service.
-   *
-   * @param \Symfony\Component\DependencyInjection\ContainerBuilder $container
-   *   The container to process.
-   */
-  public function process(ContainerBuilder $container) {
-    if (!$container->hasDefinition('paramconverter_manager')) {
-      return;
-    }
-
-    $manager = $container->getDefinition('paramconverter_manager');
-    foreach ($container->findTaggedServiceIds('paramconverter') as $id => $attributes) {
-      $priority = isset($attributes[0]['priority']) ? $attributes[0]['priority'] : 0;
-      $manager->addMethodCall('addConverter', array($id, $priority));
-    }
-  }
-}