title: What the RequestContext parameter in GetControllerInstance method of DefaultControllerFactory is for?
body: <p>I stumbled upon this method</p>
  
  <pre><code>protected internal virtual IController GetControllerInstance(RequestContext requestContext, Type controllerType)
      {
          if (controllerType == null)
          {
              throw new HttpException(404,
                                      String.Format(
                                          CultureInfo.CurrentCulture,
                                          MvcResources.DefaultControllerFactory_NoControllerFound,
                                          requestContext.HttpContext.Request.Path));
          }
          if (!typeof(IController).IsAssignableFrom(controllerType))
          {
              throw new ArgumentException(
                  String.Format(
                      CultureInfo.CurrentCulture,
                      MvcResources.DefaultControllerFactory_TypeDoesNotSubclassControllerBase,
                      controllerType),
                  "controllerType");
          }
          return ControllerActivator.Create(requestContext, controllerType);
      }
  </code></pre>
  
  <p>and I'm wondering what the requestContext parameter is for since it seems it's never used. It's passed to ControllerActivator.Create but it never really used there either:</p>
  
  <pre><code>public IController Create(RequestContext requestContext, Type controllerType)
          {
              try
              {
                  return (IController)(_resolverThunk().GetService(controllerType) ?? Activator.CreateInstance(controllerType));
              }
              catch (Exception ex)
              {
                  throw new InvalidOperationException(
                      String.Format(
                          CultureInfo.CurrentCulture,
                          MvcResources.DefaultControllerFactory_ErrorCreatingController,
                          controllerType),
                      ex);
              }
          }
  </code></pre>