Fix update and enrollment flow

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

 // Copyright (c) 2011 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_update_screen.h"
 
 namespace chromeos {
 
 using ::testing::AtLeast;
 using ::testing::NotNull;
 
 MockUpdateScreen::MockUpdateScreen(ScreenObserver* screen_observer,
                                    UpdateScreenActor* actor)
-    : UpdateScreen(screen_observer, actor) {
+    : UpdateScreen(screen_observer, actor, NULL) {
 }
 
 MockUpdateScreen::~MockUpdateScreen() {
 }
 
 MockUpdateScreenActor::MockUpdateScreenActor()
     : screen_(NULL) {
   EXPECT_CALL(*this, MockSetDelegate(NotNull())).Times(AtLeast(1));
 }
 
 MockUpdateScreenActor::~MockUpdateScreenActor() {
   if (screen_)
     screen_->OnActorDestroyed(this);
 }
 
 void MockUpdateScreenActor::SetDelegate(UpdateScreenActor::Delegate* screen) {
   screen_ = screen;
   MockSetDelegate(screen);
 }
 
 }  // namespace chromeos