Remove dead requries to AC integration. Rely on autoloads instead

railties/lib/performance_test_help.rb

-require 'action_controller/testing/performance_test'
-
 ActionController::Base.perform_caching = true
 ActiveSupport::Dependencies.mechanism = :require
 Rails.logger.level = ActiveSupport::BufferedLogger::INFO

railties/lib/test_help.rb

@@ -8,9 +8,7 @@
 
 require 'test/unit'
 require 'active_support/core_ext/kernel/requires'
-require 'action_controller/testing/test_case'
 require 'action_view/test_case'
-require 'action_controller/testing/integration'
 require 'action_mailer/test_case' if defined?(ActionMailer)
 
 if defined?(ActiveRecord)

railties/test/rails_info_controller_test.rb

 require 'abstract_unit'
 require 'action_controller'
-require 'action_controller/testing/process'
 
 require 'rails/info'
 require 'rails/info_controller'