Replace global Hash with TS::Cache.

Conflicts:
	actionpack/lib/action_dispatch/journey/visitors.rb

Author: thedarkone

actionpack/lib/action_dispatch/journey/visitors.rb

@@ -1,10 +1,13 @@
 # encoding: utf-8
+
+require 'thread_safe'
+
 module ActionDispatch
   module Journey # :nodoc:
     module Visitors # :nodoc:
       class Visitor # :nodoc:
-        DISPATCH_CACHE = Hash.new { |h,k|
-          h[k] = "visit_#{k}"
+        DISPATCH_CACHE = ThreadSafe::Cache.new { |h,k|
+          h[k] = :"visit_#{k}"
         }
 
         def accept(node)