This provides a simple interface for gr-change-actions for use by
the JS API. It allows the author to not have to worry about
implementation details of the element itself, while still
providing a reduced-surface API contract that can be tested as
the underlying element evolves.
Feature: Issue 3915
Change-Id: I2f82060ea14adef93a7018b79bf7cf10b84e5735
a6eb943825