Revert 37b0690fb8.

This feature causes more problems than it solves.

lib/action_controller/serialization.rb

@@ -30,17 +30,6 @@ module ActionController
     included do
       class_attribute :_serialization_scope
       self._serialization_scope = :current_user
-
-      unless self.respond_to?(:responder=)
-        include ActionController::MimeResponds
-      end
-
-      self.responder = ActiveModel::Serializer::Responder
-      self.respond_to :json
-
-      unless ActiveModel::Serializer.use_default_render_json
-        self.send(:include, RenderJsonOverride)
-      end
     end
 
     def serialization_scope
@@ -50,15 +39,13 @@ module ActionController
     def default_serializer_options
     end
 
-    module RenderJsonOverride
-      def _render_option_json(resource, options)
-        json = ActiveModel::Serializer.build_json(self, resource, options)
+    def _render_option_json(resource, options)
+      json = ActiveModel::Serializer.build_json(self, resource, options)
 
-        if json
-          super(json, options)
-        else
-          super
-        end
+      if json
+        super(json, options)
+      else
+        super
       end
     end
 

lib/active_model/serializer.rb

@@ -66,9 +66,6 @@ module ActiveModel
     self._embed = :objects
     class_attribute :_root_embed
 
-    class_attribute :use_default_render_json
-    self.use_default_render_json = false
-
     class_attribute :cache
     class_attribute :perform_caching
 

lib/active_model/serializer/responder.rb

@@ -1,21 +0,0 @@
-module ActiveModel
-  class Serializer
-    class Responder < ::ActionController::Responder #:nodoc:
-
-    protected
-      def display(resource, given_options = {})
-        if format != :json
-          super
-        else
-          json = Serializer.build_json(controller, resource, options)
-
-          if json
-            render given_options.merge(options).merge(:json => json)
-          else
-            super
-          end
-        end
-      end
-    end
-  end
-end

lib/active_model_serializers.rb

@@ -86,7 +86,6 @@ begin
   require 'action_controller/serialization'
 
   ActiveSupport.on_load(:action_controller) do
-    require 'active_model/serializer/responder'
     include ::ActionController::Serialization
   end
 rescue LoadError => ex