Use a when clause for the Class check

Author: rafaelfranca

actionpack/lib/action_controller/metal/request_forgery_protection.rb

@@ -164,15 +164,15 @@ def skip_forgery_protection(options = {})
 
       private
         def protection_method_class(name)
-          return name if name.is_a?(Class)
-
           case name
           when :null_session
             ProtectionMethods::NullSession
           when :reset_session
             ProtectionMethods::ResetSession
           when :exception
             ProtectionMethods::Exception
+          when Class
+            name
           else
             raise ArgumentError, "Invalid request forgery protection method, use :null_session, :exception, :reset_session, or a custom forgery protection class."
           end