28 files declare their use of DependentPluginInterface in Drupal 8
- AggregatorPluginSettingsBase.php in core/
modules/ aggregator/ src/ Plugin/ AggregatorPluginSettingsBase.php  - ArgumentPluginBase.php in core/
modules/ views/ src/ Plugin/ views/ argument/ ArgumentPluginBase.php  - BlockPluginInterface.php in core/
lib/ Drupal/ Core/ Block/ BlockPluginInterface.php  - ConditionInterface.php in core/
lib/ Drupal/ Core/ Condition/ ConditionInterface.php  - Config.php in core/
modules/ migrate/ src/ Plugin/ migrate/ destination/ Config.php  - ConfigurableActionBase.php in core/
lib/ Drupal/ Core/ Action/ ConfigurableActionBase.php  - ConfigurableSearchPluginInterface.php in core/
modules/ search/ src/ Plugin/ ConfigurableSearchPluginInterface.php  - ContextHandlerTest.php in core/
tests/ Drupal/ Tests/ Core/ Plugin/ ContextHandlerTest.php  - Contains \Drupal\Tests\Core\Plugin\ContextHandlerTest.
 - DisplayPluginBase.php in core/
modules/ views/ src/ Plugin/ views/ display/ DisplayPluginBase.php  - DrupalSqlBase.php in core/
modules/ migrate_drupal/ src/ Plugin/ migrate/ source/ DrupalSqlBase.php  - EmptySource.php in core/
modules/ migrate_drupal/ src/ Plugin/ migrate/ source/ EmptySource.php  - Entity.php in core/
modules/ migrate/ src/ Plugin/ migrate/ destination/ Entity.php  - EntityActionBase.php in core/
lib/ Drupal/ Core/ Action/ Plugin/ Action/ EntityActionBase.php  - EntityField.php in core/
modules/ views/ src/ Plugin/ views/ field/ EntityField.php  - EntityResource.php in core/
modules/ rest/ src/ Plugin/ rest/ resource/ EntityResource.php  - FilterInterface.php in core/
modules/ filter/ src/ Plugin/ FilterInterface.php  - ImageEffectInterface.php in core/
modules/ image/ src/ ImageEffectInterface.php  - LayoutInterface.php in core/
lib/ Drupal/ Core/ Layout/ LayoutInterface.php  - LayoutTestDependenciesPlugin.php in core/
modules/ system/ tests/ modules/ layout_test/ src/ Plugin/ Layout/ LayoutTestDependenciesPlugin.php  - MediaSourceInterface.php in core/
modules/ media/ src/ MediaSourceInterface.php  - PluginBase.php in core/
modules/ views/ src/ Plugin/ views/ PluginBase.php  - PluginDependencyTrait.php in core/
lib/ Drupal/ Core/ Plugin/ PluginDependencyTrait.php  - PluginDependencyTraitTest.php in core/
tests/ Drupal/ Tests/ Core/ Plugin/ PluginDependencyTraitTest.php  - PluginSettingsBase.php in core/
lib/ Drupal/ Core/ Field/ PluginSettingsBase.php  - SelectionPluginBase.php in core/
lib/ Drupal/ Core/ Entity/ EntityReferenceSelection/ SelectionPluginBase.php  - TestConfigurablePlugin.php in core/
tests/ Drupal/ Tests/ Core/ Plugin/ Fixtures/ TestConfigurablePlugin.php  - VariantInterface.php in core/
lib/ Drupal/ Core/ Display/ VariantInterface.php  - WorkflowTypeInterface.php in core/
modules/ workflows/ src/ WorkflowTypeInterface.php