ScreenObserver is renamed to BaseScreenDelegate.

chrome/browser/chromeos/login/screens/mock_error_screen.cc

 // Copyright (c) 2013 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/screens/mock_error_screen.h"
 
 namespace chromeos {
 
-MockErrorScreen::MockErrorScreen(ScreenObserver* screen_observer,
+MockErrorScreen::MockErrorScreen(BaseScreenDelegate* base_screen_delegate,
                                  ErrorScreenActor* actor)
-    : ErrorScreen(screen_observer, actor) {
+    : ErrorScreen(base_screen_delegate, actor) {
 }
 
 MockErrorScreen::~MockErrorScreen() {
 }
 
 MockErrorScreenActor::MockErrorScreenActor() {
 }
 
 MockErrorScreenActor::~MockErrorScreenActor() {
 }
 
-}  // namespace chromeosx
+}  // namespace chromeos