ScreenObserver is renamed to BaseScreenDelegate.

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

Index: chrome/browser/chromeos/login/screens/device_disabled_screen.h
diff --git a/chrome/browser/chromeos/login/screens/device_disabled_screen.h b/chrome/browser/chromeos/login/screens/device_disabled_screen.h
index 12bd2b7410290c524a3d75340fc5103843743f82..e9d2fe34cef7af6c720dbcde986f613e857aaab2 100644
--- a/chrome/browser/chromeos/login/screens/device_disabled_screen.h
+++ b/chrome/browser/chromeos/login/screens/device_disabled_screen.h
@@ -12,13 +12,13 @@
 
 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;