This is called for activities that set launchMode to "singleTop" in their package, or if a client used the Android.Content.Intent.FLAG_ACTIVITY_SINGLE_TOP flag when calling Activity.startActivity(android.content.Intent). In either case, when the activity is re-launched while at the top of the activity stack instead of a new instance of the activity being started, onNewIntent() will be called on the existing instance with the Intent that was used to re-launch it.

An activity will always be paused before receiving a new intent, so you can count on Activity.OnResume being called after this method.

Note that Activity.Intent still returns the original Intent. You can use Activity.Intent to update it to this new Intent.

[Android Documentation]