12 files declare their use of InboundPathProcessorInterface

AliasPathProcessor.php in core/modules/path_alias/src/PathProcessor/AliasPathProcessor.php
BrokenInboundPathProcessor.php in core/modules/system/tests/modules/update_script_test/src/PathProcessor/BrokenInboundPathProcessor.php
ConfigTranslationController.php in core/modules/config_translation/src/Controller/ConfigTranslationController.php
LanguageNegotiationUrl.php in core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationUrl.php
PathBasedBreadcrumbBuilder.php in core/modules/system/src/PathBasedBreadcrumbBuilder.php
PathProcessor.php in core/modules/system/tests/modules/url_alter_test/src/PathProcessor.php
PathProcessorFiles.php in core/modules/system/src/PathProcessor/PathProcessorFiles.php
PathProcessorImageStyles.php in core/modules/image/src/PathProcessor/PathProcessorImageStyles.php
PathProcessorLanguage.php in core/modules/language/src/HttpKernel/PathProcessorLanguage.php
PathProcessorTest.php in core/modules/system/tests/modules/url_alter_test/src/PathProcessorTest.php
PathValidator.php in core/lib/Drupal/Core/Path/PathValidator.php
RouteProvider.php in core/lib/Drupal/Core/Routing/RouteProvider.php

Buggy or inaccurate documentation? Please file an issue. Need support? Need help programming? Connect with the Drupal community.