12 files declare their use of EntityChangedInterface in Zircon Profile 8

BlockContentInterface.php in core/modules/block_content/src/BlockContentInterface.php

Contains \Drupal\block_content\BlockContentInterface.

CommentInterface.php in core/modules/comment/src/CommentInterface.php

Contains \Drupal\comment\CommentInterface.

CommentStatistics.php in core/modules/comment/src/CommentStatistics.php

Contains \Drupal\comment\CommentStatistics.

EntityTestConstraints.php in core/modules/system/tests/modules/entity_test/src/Entity/EntityTestConstraints.php

Contains \Drupal\entity_test\Entity\EntityTestConstraints.

EntityTestMulChanged.php in core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMulChanged.php

Contains \Drupal\entity_test\Entity\EntityTestMulChanged.

FileInterface.php in core/modules/file/src/FileInterface.php

Contains \Drupal\file\FileInterface.

MenuLinkContentInterface.php in core/modules/menu_link_content/src/MenuLinkContentInterface.php

Contains \Drupal\menu_link_content\MenuLinkContentInterface.

NodeInterface.php in core/modules/node/src/NodeInterface.php

Contains \Drupal\node\NodeInterface.

QuickEditFieldForm.php in core/modules/quickedit/src/Form/QuickEditFieldForm.php

Contains \Drupal\quickedit\Form\QuickEditFieldForm.

ShortcutTranslationUITest.php in core/modules/shortcut/src/Tests/ShortcutTranslationUITest.php

Contains \Drupal\shortcut\Tests\ShortcutTranslationUITest.

TermInterface.php in core/modules/taxonomy/src/TermInterface.php

Contains \Drupal\taxonomy\TermInterface.

UserInterface.php in core/modules/user/src/UserInterface.php

Contains \Drupal\user\UserInterface.