Make performance tests work again

actionpack/lib/action_controller/testing/performance.rb

-require 'active_support/testing/performance'
-require 'active_support/testing/default'
-
-module ActionController
-  # An integration test that runs a code profiler on your test methods.
-  # Profiling output for combinations of each test method, measurement, and
-  # output format are written to your tmp/performance directory.
-  #
-  # By default, process_time is measured and both flat and graph_html output
-  # formats are written, so you'll have two output files per test method.
-  class PerformanceTest < ActionController::IntegrationTest
-    include ActiveSupport::Testing::Performance
-    include ActiveSupport::Testing::Default
-  end
-end

railties/lib/performance_test_help.rb

-require 'action_controller/performance_test'
+require 'action_controller/testing/performance_test'
 
 ActionController::Base.perform_caching = true
 ActiveSupport::Dependencies.mechanism = :require