GitHub: https://github.com/Unity-Technologies/InputSystem/issues/467

Repro:
1. Download package and project at: https://github.com/Unity-Technologies/InputSystem
2. Right click in the Project window to create a new InputAction or open an existing one
3. In the UI, create new Action Maps and Input Action if there is none
4. Pick a binding, in the Properites, click the ◉ button then press any key to bind it
5. If the error doesn't appear, repeat the last step several times.

Actual: Memory leak error occurs when using UI to bind to an Action through detecting input