This (and the removal of `.call` below) seem to be unrelated to the rest of the PR?  I think the change is ok since it is equivalent to the [normal listener invoking](https://github.com/angular/angular.js/blob/4487d4a8a477ad440500e3574c141da48d13ab3d/src/ng/rootScope.js#L803). But I think the idea of doing .call/apply here was to avoid duplicating that logic. 