ScreenObserver is renamed to BaseScreenDelegate.

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

 // Copyright (c) 2012 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_USER_IMAGE_SCREEN_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_USER_IMAGE_SCREEN_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/chromeos/camera_presence_notifier.h"
@@ skipping 19 matching lines @@
 class UserImageManager;
 class ScreenManager;
 
 class UserImageScreen : public BaseScreen,
                         public UserImageScreenActor::Delegate,
                         public ImageDecoder::Delegate,
                         public content::NotificationObserver,
                         public UserImageSyncObserver::Observer,
                         public CameraPresenceNotifier::Observer {
  public:
-  UserImageScreen(ScreenObserver* screen_observer,
+  UserImageScreen(BaseScreenDelegate* base_screen_delegate,
                   UserImageScreenActor* actor);
   virtual ~UserImageScreen();
 
   static UserImageScreen* Get(ScreenManager* manager);
 
   // BaseScreen implementation:
   virtual void PrepareToShow() override;
   virtual void Show() override;
   virtual void Hide() override;
   virtual std::string GetName() const override;
@@ skipping 91 matching lines @@
 
   // True if user has explicitly selected some image.
   bool user_has_selected_image_;
 
   DISALLOW_COPY_AND_ASSIGN(UserImageScreen);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_USER_IMAGE_SCREEN_H_