Get rid of prepare_each_request, since now it's a middleware initialization parameter.

actionpack/lib/action_controller/deprecated/dispatcher.rb

 module ActionController
   class Dispatcher
-    cattr_accessor :prepare_each_request
-    self.prepare_each_request = false
-
     class << self
       def before_dispatch(*args, &block)
         ActiveSupport::Deprecation.warn "ActionController::Dispatcher.before_dispatch is deprecated. " <<

actionpack/lib/action_controller/railtie.rb

@@ -73,7 +73,6 @@ def name
       # TODO: This used to say unless defined?(Dispatcher). Find out why and fix.
       # Notice that at this point, ActionDispatch::Callbacks were already loaded.
       require 'rails/dispatcher'
-      ActionController::Dispatcher.prepare_each_request = true unless app.config.cache_classes
 
       unless app.config.cache_classes
         # Setup dev mode route reloading

railties/lib/rails/configuration.rb

@@ -15,7 +15,7 @@ def self.default_middleware_stack
         middleware.use('::Rack::Runtime')
         middleware.use('ActionDispatch::ShowExceptions', lambda { ActionController::Base.consider_all_requests_local })
         middleware.use('ActionDispatch::Notifications')
-        middleware.use('ActionDispatch::Callbacks', lambda { ActionController::Dispatcher.prepare_each_request })
+        middleware.use('ActionDispatch::Callbacks', lambda { !Rails.application.config.cache_classes })
         middleware.use('ActionDispatch::Cookies')
         middleware.use(lambda { ActionController::Base.session_store }, lambda { ActionController::Base.session_options })
         middleware.use('ActionDispatch::Flash', :if => lambda { ActionController::Base.session_store })