Remove deprecated attr_protected/accessible

Rails 4.0 has removed attr_protected and attr_accessible feature in favor of Strong Parameters.

activemodel/lib/active_model.rb

@@ -37,7 +37,6 @@ module ActiveModel
   autoload :ForbiddenAttributesProtection
   autoload :Lint
   autoload :Model
-  autoload :DeprecatedMassAssignmentSecurity
   autoload :Name, 'active_model/naming'
   autoload :Naming
   autoload :SecurePassword

activemodel/lib/active_model/deprecated_mass_assignment_security.rb

@@ -1,21 +0,0 @@
-module ActiveModel
-  module DeprecatedMassAssignmentSecurity # :nodoc:
-    extend ActiveSupport::Concern
-
-     module ClassMethods # :nodoc:
-       def attr_protected(*args)
-         raise "`attr_protected` is extracted out of Rails into a gem. " \
-           "Please use new recommended protection model for params" \
-           "(strong_parameters) or add `protected_attributes` to your " \
-           "Gemfile to use old one."
-       end
-
-       def attr_accessible(*args)
-         raise "`attr_accessible` is extracted out of Rails into a gem. " \
-           "Please use new recommended protection model for params" \
-           "(strong_parameters) or add `protected_attributes` to your " \
-           "Gemfile to use old one."
-       end
-     end
-  end
-end

activemodel/test/cases/deprecated_mass_assignment_security_test.rb

@@ -1,16 +0,0 @@
-require 'cases/helper'
-require 'models/project'
-
-class DeprecatedMassAssignmentSecurityTest < ActiveModel::TestCase
-  def test_attr_accessible_raise_error
-    assert_raise RuntimeError, /protected_attributes/ do
-      Project.attr_accessible :username
-    end
-  end
-
-  def test_attr_protected_raise_error
-    assert_raise RuntimeError, /protected_attributes/ do
-      Project.attr_protected :username
-    end
-  end
-end

activerecord/lib/active_record/attribute_assignment.rb

@@ -3,7 +3,6 @@
 module ActiveRecord
   module AttributeAssignment
     extend ActiveSupport::Concern
-    include ActiveModel::DeprecatedMassAssignmentSecurity
     include ActiveModel::ForbiddenAttributesProtection
 
     # Allows you to set all the attributes by passing in a hash of attributes with