CameraPresenceNotifier observers removal supported.

chrome/browser/chromeos/login/screens/user_image_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_SCREENS_USER_IMAGE_SCREEN_ACTOR_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_USER_IMAGE_SCREEN_ACTOR_H_
 
 #include <string>
 
 #include "chrome/browser/chromeos/camera_presence_notifier.h"
 
 class SkBitmap;
 
 namespace gfx {
 class ImageSkia;
 }
 
 namespace chromeos {
 
 // Interface for dependency injection between UserImageScreen and its actual
 // representation, either views based or WebUI.
 class UserImageScreenActor {
  public:
   class Delegate : public CameraPresenceNotifier::Observer {
    public:
-    virtual ~Delegate() {}
+    virtual ~Delegate() {
+      CameraPresenceNotifier::GetInstance()->RemoveObserver(this);

[ygorshenin1, 2014/04/03 11:45:49]

No need to call RemoveObserver() here. It'll be called in dtor of
CameraPresenceNotifier::Observer.

+    }
 
     // CameraPresenceNotifier::Observer implementation:
     virtual void OnCameraPresenceCheckDone(bool is_camera_present) = 0;
 
     // Called when UI ready to be shown.
     virtual void OnScreenReady() = 0;
     // Called when user accepts photo as login user image.
     virtual void OnPhotoTaken(const std::string& raw_data) = 0;
 
     // Called when some image was selected. |is_user_selection| indicates if
@@ skipping 42 matching lines @@
   // Sends result of camera check
   virtual void SetCameraPresent(bool enabled) = 0;
 
   // Hides curtain with spinner.
   virtual void HideCurtain() = 0;
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_USER_IMAGE_SCREEN_ACTOR_H_