Revert "Merge pull request #20851 from tomprats/indifferent-sessions"

This reverts commit 22db455d, reversing
changes made to 40be61df.

This finishes off what I meant to do in 6216a092.

actionpack/CHANGELOG.md

@@ -29,15 +29,6 @@
 
 ## Rails 5.0.0.beta3 (February 24, 2016) ##
 
-*   Update session to have indifferent access across multiple requests.
-
-        session[:deep][:hash] = "Magic"
-
-        session[:deep][:hash] == "Magic"
-        session[:deep]["hash"] == "Magic"
-
-    *Tom Prats*
-
 *   Add application/gzip as a default mime type.
 
     *Mehmet Emin İNAÇ*

actionpack/lib/action_dispatch/request/session.rb

@@ -9,7 +9,7 @@ class Session # :nodoc:
 
       # Singleton object used to determine if an optional param wasn't specified
       Unspecified = Object.new
-
+      
       # Creates a session hash, merging the properties of the previous session if any
       def self.create(store, req, default_options)
         session_was = find req
@@ -61,7 +61,7 @@ def values_at(*args); @delegate.values_at(*args); end
       def initialize(by, req)
         @by       = by
         @req      = req
-        @delegate = {}.with_indifferent_access
+        @delegate = {}
         @loaded   = false
         @exists   = nil # we haven't checked yet
       end

actionpack/test/dispatch/request/session_test.rb

@@ -105,16 +105,6 @@ def test_fetch
         end
       end
 
-      def test_with_indifferent_access
-        s = Session.create(store, req, {})
-
-        s[:one] = { test: "deep" }
-        s[:two] = { "test" => "deep" }
-
-        assert_equal 'deep', s[:one]["test"]
-        assert_equal 'deep', s[:two][:test]
-      end
-
       private
       def store
         Class.new {