¿Cómo puedo desactivar cors? Por alguna razón, puse en relieve los orígenes y encabezados permitidos, pero mis solicitudes de ajax aún se quejan de que mi política CORS no permite el origen ...

Mi controlador de aplicaciones:

class ApplicationController < ActionController::Base
  protect_from_forgery
  before_filter :current_user, :cors_preflight_check
  after_filter :cors_set_access_control_headers

# For all responses in this controller, return the CORS access control headers.

def cors_set_access_control_headers
  headers['Access-Control-Allow-Origin'] = '*'
  headers['Access-Control-Allow-Methods'] = 'POST, GET, OPTIONS'
  headers['Access-Control-Allow-Headers'] = '*'
  headers['Access-Control-Max-Age'] = "1728000"
end

# If this is a preflight OPTIONS request, then short-circuit the
# request, return only the necessary headers and return an empty
# text/plain.

def cors_preflight_check
  if request.method == :options
    headers['Access-Control-Allow-Origin'] = '*'
    headers['Access-Control-Allow-Methods'] = 'POST, GET, OPTIONS'
    headers['Access-Control-Allow-Headers'] = '*'
    headers['Access-Control-Max-Age'] = '1728000'
    render :text => '', :content_type => 'text/plain'
  end
end
  private
  # get the user currently logged in
  def current_user
    @current_user ||= User.find(session[:user_id]) if session[:user_id]
  end
  helper_method :current_user

end

rutas:

  match "*all" => "application#cors_preflight_check", :constraints => { :method => "OPTIONS" }
  match "/alert" => "alerts#create"
  match "/alerts" => "alerts#get"
  match "/login" => "sessions#create"
  match "/logout" => "sessions#destroy"
  match "/register" => "users#create"

Editar---

También intenté:

   config.middleware.use Rack::Cors do
      allow do
        origins '*'
        resource '*', 
            :headers => :any, 
            :methods => [:get, :post, :delete, :put, :options]
      end
    end

en application.rb

--edit 2 ---

El problema es que Chrome Extensions puede no ser compatible con CORS, creo. ¿Cómo puedo obtener información sin pasar por CORS? ¿Cómo debo responder a la verificación previa?