Fix incorrect handling of UNKNOWN captive portal state by supervised user creation screen.

chrome/browser/chromeos/login/supervised/supervised_user_creation_screen.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/login/supervised/supervised_user_creation_screen.h"
 
 #include "ash/desktop_background/desktop_background_controller.h"
 #include "ash/shell.h"
 #include "base/rand_util.h"
 #include "base/values.h"
@@ skipping 138 matching lines @@
 void SupervisedUserCreationScreen::OnPageSelected(const std::string& page) {
   last_page_ = page;
 }
 
 void SupervisedUserCreationScreen::OnPortalDetectionCompleted(
     const NetworkState* network,
     const NetworkPortalDetector::CaptivePortalState& state)  {
   if (state.status == NetworkPortalDetector::CAPTIVE_PORTAL_STATUS_ONLINE) {
     get_base_screen_delegate()->HideErrorScreen(this);
     histogram_helper_->OnErrorHide();
-  } else {
+  } else if (state.status !=
+             NetworkPortalDetector::CAPTIVE_PORTAL_STATUS_UNKNOWN) {
     on_error_screen_ = true;
     ErrorScreen* screen = get_base_screen_delegate()->GetErrorScreen();
     ConfigureErrorScreen(screen, network, state.status);
     screen->SetUIState(NetworkError::UI_STATE_SUPERVISED);
     get_base_screen_delegate()->ShowErrorScreen();
     histogram_helper_->OnErrorShow(screen->GetErrorState());
   }
 }
 
 void SupervisedUserCreationScreen::ShowManagerInconsistentStateErrorScreen() {
@@ skipping 451 matching lines @@
     selected_image_ = user_manager::User::USER_IMAGE_EXTERNAL;
   } else {
     NOTREACHED() << "Unexpected image type: " << image_type;
   }
 }
 
 void SupervisedUserCreationScreen::OnImageAccepted() {
 }
 
 }  // namespace chromeos