7 files declare their use of DefaultLazyPluginCollection in Zircon Profile 8

ConditionPluginCollection.php in core/lib/Drupal/Core/Condition/ConditionPluginCollection.php

Contains \Drupal\Core\Condition\ConditionPluginCollection.

DisplayPluginCollection.php in core/modules/views/src/DisplayPluginCollection.php

Contains \Drupal\views\DisplayPluginCollection.

EntityDisplayPluginCollection.php in core/lib/Drupal/Core/Entity/EntityDisplayPluginCollection.php

Contains \Drupal\Core\Entity\EntityDisplayPluginCollection.

FilterPluginCollection.php in core/modules/filter/src/FilterPluginCollection.php

Contains \Drupal\filter\FilterPluginCollection.

ImageEffectPluginCollection.php in core/modules/image/src/ImageEffectPluginCollection.php

Contains \Drupal\image\ImageEffectPluginCollection.

LazyPluginCollectionTestBase.php in core/tests/Drupal/Tests/Core/Plugin/LazyPluginCollectionTestBase.php

Contains \Drupal\Tests\Core\Plugin\LazyPluginCollectionTestBase.

TipsPluginCollection.php in core/modules/tour/src/TipsPluginCollection.php

Contains \Drupal\tour\TipsPluginCollection.