EditorSceneManager.SceneClosingCallback

public delegate void SceneClosingCallback(SceneManagement.Scene scene, bool removingScene);

Parameters

scene		The Scene that is going to be closed.
removingScene		Whether or not the Scene is also going to be removed from the Scene Manager after closing. If true the Scene is removed after closing.

Callbacks of this type which have been added to the sceneClosing event are called just before a Scene is closed.