--- /dev/null
+<?php
+
+namespace Drupal\content_moderation;
+
+/**
+ * Tracks metadata about revisions across content entities.
+ */
+interface RevisionTrackerInterface {
+
+ /**
+ * Sets the latest revision of a given entity.
+ *
+ * @param string $entity_type_id
+ * The machine name of the type of entity.
+ * @param string $entity_id
+ * The Entity ID in question.
+ * @param string $langcode
+ * The langcode of the revision we're saving. Each language has its own
+ * effective tree of entity revisions, so in different languages
+ * different revisions will be "latest".
+ * @param int $revision_id
+ * The revision ID that is now the latest revision.
+ *
+ * @return static
+ */
+ public function setLatestRevision($entity_type_id, $entity_id, $langcode, $revision_id);
+
+}