Do not eagerly load Request before initializers

Without those changes the configurations to ActionDispatch::Request
could not be applied in initializers.

actionpack/lib/action_dispatch/middleware/cookies.rb

@@ -7,7 +7,7 @@
 require "rack/utils"
 
 module ActionDispatch
-  class Request
+  module RequestCookieMethods
     def cookie_jar
       fetch_header("action_dispatch.cookies") do
         self.cookie_jar = Cookies::CookieJar.build(self, cookies)
@@ -88,6 +88,10 @@ def use_cookies_with_metadata
     # :startdoc:
   end
 
+  ActiveSupport.on_load(:action_dispatch_request) do
+    include RequestCookieMethods
+  end
+
   # Read and write data to cookies through ActionController#cookies.
   #
   # When reading cookie data, the data is read from the HTTP request header, Cookie.

actionpack/lib/action_dispatch/railtie.rb

@@ -41,8 +41,11 @@ class Railtie < Rails::Railtie # :nodoc:
     initializer "action_dispatch.configure" do |app|
       ActionDispatch::Http::URL.secure_protocol = app.config.force_ssl
       ActionDispatch::Http::URL.tld_length = app.config.action_dispatch.tld_length
-      ActionDispatch::Request.ignore_accept_header = app.config.action_dispatch.ignore_accept_header
-      ActionDispatch::Request::Utils.perform_deep_munge = app.config.action_dispatch.perform_deep_munge
+
+      ActiveSupport.on_load(:action_dispatch_request) do
+        self.ignore_accept_header = app.config.action_dispatch.ignore_accept_header
+        ActionDispatch::Request::Utils.perform_deep_munge = app.config.action_dispatch.perform_deep_munge
+      end
 
       ActiveSupport.on_load(:action_dispatch_response) do
         self.default_charset = app.config.action_dispatch.default_charset || app.config.encoding

actionpack/lib/action_dispatch/routing/route_set.rb

@@ -6,7 +6,6 @@
 require "active_support/core_ext/module/remove_method"
 require "active_support/core_ext/array/extract_options"
 require "action_controller/metal/exceptions"
-require "action_dispatch/http/request"
 require "action_dispatch/routing/endpoint"
 
 module ActionDispatch