How can I access AnimationStates outside of play mode? (Legacy Animation)

I'm trying to write an editor script which acts on the AnimationStates in an Animation component. Say that I have the following code:

 var _player = GetComponent<Animation>();
 List<AnimationState> states = new List<AnimationState>(_player.Cast<AnimationState>());
 int count = states.Count;
 for (int i = 0; i < count; ++i)
 {
     Debug.Log(i + ": " + states[i].name);
 }

This code works, but it only works after running play mode! If I modify the animation clips in the array, such as by adding or deleting clips, those modifications will not show up until after I hit play. This makes it very difficult to work with them in an editor script.

So what can I do? Is there a decent way to get the Animation component to update its list of AnimationStates from code? Thanks!