chrome: Cleanup class/struct forward declarations

chrome/browser/chromeos/login/screens/network_error_model.h

 // Copyright 2015 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_NETWORK_ERROR_MODEL_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_NETWORK_ERROR_MODEL_H_
 
 #include "base/callback_list.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/chromeos/login/screens/base_screen.h"
 #include "chrome/browser/chromeos/login/screens/network_error.h"
 #include "chrome/browser/ui/webui/chromeos/login/oobe_screen.h"
 
-namespace base {
-class ListValue;
-}
-
 namespace chromeos {
 
 class BaseScreenDelegate;
 class NetworkErrorView;
 
 class NetworkErrorModel : public BaseScreen {
  public:
   static const char kContextKeyErrorStateCode[];
   static const char kContextKeyErrorStateNetwork[];
   static const char kContextKeyGuestSigninAllowed[];
@@ skipping 56 matching lines @@
   // Shows captive portal dialog.
   virtual void ShowCaptivePortal() = 0;
 
   // Toggles the connection pending indicator.
   virtual void ShowConnectingIndicator(bool show) = 0;
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_NETWORK_ERROR_MODEL_H_