Dependency injection versus Service Locator pattern

DI.php

<?php

// Dependency

class Dependency
{
}

// Service

class Service
{
    public function __construct(Dependency $dependency) {}
}

// Factory

$sl->setService('dependency', new Dependency);

$sl->setFactory('service', function($sl) {
    $dependency = $sl->get('dependency');
    $service    = new Service($dependency);

    return $service;
});

SL.php

<?php

// Dependency

class Dependency
{
}

// Service

class Service
{
    public function __construct(ServiceLocator $sl)
    {
        $dependency = $sl->get('dependency');
    }
}

// Factory

$sl->setService('dependency', new Dependency);

$sl->setFactory('service', function($sl) {
    $service    = new Service($sl);

    return $service;
});