Forwarding onActivityResult from Activity to Fragment in android

I am trying to implement Facebook login for my android app. However, instead of using the LoginActivity, as suggested on the developer website, I have added the Facebook login button on a separate fragment. This fragment simply holds the button and does all the processing, which otherwise the LoginActivity would have done. The purpose of using a separate fragment is to prevent doing everything in the LoginActivity, specially if other login options like Google+ also exist.

Now the problem is that the UiLifecycleHelper constructor accepts only Activity object for callbacks:

UiLifecycleHelper(Activity, StatusCallback)

Because of this, I am bound to do something like:

UiLifecycleHelper(getActivity(), callback)

So, eventually:

@override
onActivityResult(...)

is called in LoginActivity, instead of in my fragment which hosts the login button.

Now the authentication won't work, unless I explicitly call onActivityResult method in the fragment from onActivityResult from the LoginActivity. Because it is the fragment who has created and is maintaining the UILifecycleHelper object.

I want to avoid adding this "hack" in the LoginActivity, specially since, there's no way for me to know if the onActivityResult was called as a result of Facebook authentication process.

What's a proper way to achieve this?