Ember.binding.or in Ember-1.9.1

I am upgrading Ember from 0.9.8 to 1.9.1

I find a line of code, where binding happens based on a logical OR condition

dirtyBinding: Ember.Binding.or('oController.isDirty', 'oController.isDirty')

How do I get this done in ember 1.9.1 as Ember.Binding.or , Ember.Binding.and seem to have deprecated.