Stop requiring mocha automatically

We are planning to remove mocha from our test suite because of
performance problems. To make this possible we should stop require mocha
on ActionSupport::TestCase.

This should not affect applications since users still need to add mocha
to Gemfile and this already load mocha.

Added FIXME notes to place that still need mocha removal

actionmailer/test/abstract_unit.rb

@@ -49,3 +49,5 @@ def rubinius_skip(message = '')
 def jruby_skip(message = '')
   skip message if defined?(JRUBY_VERSION)
 end
+
+require 'mocha/setup' # FIXME: stop using mocha

actionpack/test/abstract_unit.rb

@@ -359,3 +359,5 @@ def rubinius_skip(message = '')
 def jruby_skip(message = '')
   skip message if defined?(JRUBY_VERSION)
 end
+
+require 'mocha/setup' # FIXME: stop using mocha

actionview/test/abstract_unit.rb

@@ -338,3 +338,5 @@ def rubinius_skip(message = '')
 def jruby_skip(message = '')
   skip message if defined?(JRUBY_VERSION)
 end
+
+require 'mocha/setup' # FIXME: stop using mocha

activemodel/test/cases/helper.rb

@@ -11,3 +11,5 @@
 I18n.enforce_available_locales = false
 
 require 'active_support/testing/autorun'
+
+require 'mocha/setup' # FIXME: stop using mocha

activerecord/test/cases/helper.rb

@@ -199,3 +199,5 @@ def in_time_zone(zone)
     ActiveRecord::Base.time_zone_aware_attributes = old_tz
   end
 end
+
+require 'mocha/setup' # FIXME: stop using mocha

activesupport/lib/active_support/test_case.rb

@@ -9,11 +9,6 @@
 require 'active_support/core_ext/kernel/reporting'
 require 'active_support/deprecation'
 
-begin
-  silence_warnings { require 'mocha/setup' }
-rescue LoadError
-end
-
 module ActiveSupport
   class TestCase < ::Minitest::Test
     Assertion = Minitest::Assertion

activesupport/test/abstract_unit.rb

@@ -36,3 +36,5 @@ def rubinius_skip(message = '')
 def jruby_skip(message = '')
   skip message if defined?(JRUBY_VERSION)
 end
+
+require 'mocha/setup' # FIXME: stop using mocha

railties/test/generators/actions_test.rb

@@ -1,6 +1,7 @@
 require 'generators/generators_test_helper'
 require 'rails/generators/rails/app/app_generator'
 require 'env_helpers'
+require 'mocha/setup' # FIXME: stop using mocha
 
 class ActionsTest < Rails::Generators::TestCase
   include GeneratorsTestHelper

railties/test/generators/app_generator_test.rb

@@ -1,6 +1,7 @@
 require 'generators/generators_test_helper'
 require 'rails/generators/rails/app/app_generator'
 require 'generators/shared_generator_tests'
+require 'mocha/setup' # FIXME: stop using mocha
 
 DEFAULT_APP_FILES = %w(
   .gitignore

railties/test/generators/named_base_test.rb

@@ -1,5 +1,6 @@
 require 'generators/generators_test_helper'
 require 'rails/generators/rails/scaffold_controller/scaffold_controller_generator'
+require 'mocha/setup' # FIXME: stop using mocha
 
 # Mock out what we need from AR::Base.
 module ActiveRecord

railties/test/generators/plugin_generator_test.rb

@@ -1,6 +1,7 @@
 require 'generators/generators_test_helper'
 require 'rails/generators/rails/plugin/plugin_generator'
 require 'generators/shared_generator_tests'
+require 'mocha/setup' # FIXME: stop using mocha
 
 DEFAULT_PLUGIN_FILES = %w(
   .gitignore

railties/test/generators_test.rb

@@ -1,6 +1,7 @@
 require 'generators/generators_test_helper'
 require 'rails/generators/rails/model/model_generator'
 require 'rails/generators/test_unit/model/model_generator'
+require 'mocha/setup' # FIXME: stop using mocha
 
 class GeneratorsTest < Rails::Generators::TestCase
   include GeneratorsTestHelper

railties/test/paths_test.rb

@@ -1,5 +1,6 @@
 require 'abstract_unit'
 require 'rails/paths'
+require 'mocha/setup' # FIXME: stop using mocha
 
 class PathsTest < ActiveSupport::TestCase
   def setup

railties/test/rails_info_controller_test.rb

@@ -1,4 +1,5 @@
 require 'abstract_unit'
+require 'mocha/setup' # FIXME: stop using mocha
 
 module ActionController
   class Base