angular/angular.js — pull request #7316 by lee-elenbaas (2014-04-30 16:02:56+00:00)
Title: fix(injector): conditionally create $delegate

On decorator instantiation, only create $delegate instance if the dependancy exists.
This allows decorators that completely replace the decorated service to be independant of the original service.

fix for https://github.com/angular/angular.js/issues/6961