Defines a set of features that may be supported by the native Message dialog exposed by the Facebook Messenger application. As additional features are added, these flags may be passed to FacebookDialog.canPresentMessageDialog(android.content.Context, com.facebook.widget.FacebookDialog.MessageDialogFeature...) to determine whether the version of the Facebook application installed on the user's device is recent enough to support specific features, which in turn may be used to determine which UI, etc., to present to the user.