12 files declare their use of EventDispatcherInterface

AbstractHasDispatcher.php in drupal/core/vendor/guzzle/common/Guzzle/Common/AbstractHasDispatcher.php
ConfigImporter.php in drupal/core/lib/Drupal/Core/Config/ConfigImporter.php
Contains \Drupal\Core\Config\ConfigImporter.
ContainerAwareHttpKernel.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/DependencyInjection/ContainerAwareHttpKernel.php
HasDispatcherInterface.php in drupal/core/vendor/guzzle/common/Guzzle/Common/HasDispatcherInterface.php
HttpKernel.php in drupal/core/lib/Drupal/Core/HttpKernel.php
Definition of Drupal\Core\HttpKernel.
HttpKernel.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpKernel.php
InlineFragmentRenderer.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Fragment/InlineFragmentRenderer.php
IoEmittingEntityBody.php in drupal/core/vendor/guzzle/http/Guzzle/Http/IoEmittingEntityBody.php
RdfMappingManager.php in drupal/core/modules/rdf/lib/Drupal/rdf/RdfMappingManager.php
Contains RdfMappingManager.
Request.php in drupal/core/vendor/guzzle/http/Guzzle/Http/Message/Request.php
RouteBuilder.php in drupal/core/lib/Drupal/Core/Routing/RouteBuilder.php
Definition of Drupal\Core\Routing\RouteBuilder.
TraceableEventDispatcher.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Debug/TraceableEventDispatcher.php