ScreenObserver is renamed to BaseScreenDelegate.

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

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_DEVICE_DISABLED_SCREEN_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_DEVICE_DISABLED_SCREEN_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/chromeos/login/screens/base_screen.h"
 #include "chrome/browser/chromeos/login/screens/device_disabled_screen_actor.h"
 
 namespace chromeos {
 
-class ScreenObserver;
+class BaseScreenDelegate;
 
 // Screen informing the user that the device has been disabled by its owner.
 class DeviceDisabledScreen : public BaseScreen,
                              public DeviceDisabledScreenActor::Delegate {
  public:
-  DeviceDisabledScreen(ScreenObserver* observer,
+  DeviceDisabledScreen(BaseScreenDelegate* base_screen_delegate,
                        DeviceDisabledScreenActor* actor);
   ~DeviceDisabledScreen() override;
 
   // BaseScreen:
   void PrepareToShow() override;
   void Show() override;
   void Hide() override;
   std::string GetName() const override;
 
   // DeviceDisabledScreenActor::Delegate:
@@ skipping 10 matching lines @@
   DeviceDisabledScreenActor* actor_;
 
   base::WeakPtrFactory<DeviceDisabledScreen> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceDisabledScreen);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_DEVICE_DISABLED_SCREEN_H_