[cros] check for updates in WebUI OOBE can be cancelled in dev builds.

chrome/browser/chromeos/login/update_screen_actor.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_UPDATE_SCREEN_ACTOR_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_UPDATE_SCREEN_ACTOR_H_
 #pragma once
 
 namespace chromeos {
 
 class WizardScreen;
 class ScreenObserver;
 
 class UpdateScreenActor {
  public:
+  class Delegate {
+   public:
+    virtual ~Delegate() {}
+    // Force cancel update.
+    virtual void CancelUpdate() = 0;
+    virtual void OnActorDestroyed(UpdateScreenActor* actor) = 0;
+  };
+
   virtual ~UpdateScreenActor() {}
 
+  // Sets screen this actor belongs to.
+  virtual void SetDelegate(Delegate* screen) = 0;
+
   // Shows the screen.
   virtual void Show() = 0;
 
   // Hides the screen.
   virtual void Hide() = 0;
 
   virtual void PrepareToShow() = 0;
 
   // Shows manual reboot info message.
   virtual void ShowManualRebootInfo() = 0;
 
   // Sets current progress in percents.
   virtual void SetProgress(int progress) = 0;
 
   // Shows screen curtains.
   virtual void ShowCurtain(bool enable) = 0;
 
   // Shows label for "Preparing updates" state.
   virtual void ShowPreparingUpdatesInfo(bool visible) = 0;
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_UPDATE_SCREEN_ACTOR_H_