cros: Fix user image change crash

chrome/browser/ui/webui/settings/chromeos/change_picture_handler.cc

 // Copyright 2015 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/ui/webui/settings/chromeos/change_picture_handler.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 64 matching lines @@
 }
 
 // Time histogram suffix for profile image download.
 const char kProfileDownloadReason[] = "Preferences";
 
 }  // namespace
 
 ChangePictureHandler::ChangePictureHandler()
     : previous_image_url_(url::kAboutBlankURL),
       previous_image_index_(user_manager::User::USER_IMAGE_INVALID),
+      user_manager_observer_(this),
       camera_observer_(this) {
   ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
   media::SoundsManager* manager = media::SoundsManager::Get();
   manager->Initialize(SOUND_OBJECT_DELETE,
                       bundle.GetRawDataResource(IDR_SOUND_OBJECT_DELETE_WAV));
   manager->Initialize(SOUND_CAMERA_SNAP,
                       bundle.GetRawDataResource(IDR_SOUND_CAMERA_SNAP_WAV));
 }
 
 ChangePictureHandler::~ChangePictureHandler() {
@@ skipping 14 matching lines @@
   web_ui()->RegisterMessageCallback(
       "onChangePicturePageInitialized",
       base::Bind(&ChangePictureHandler::HandlePageInitialized,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
       "selectImage", base::Bind(&ChangePictureHandler::HandleSelectImage,
                                 base::Unretained(this)));
 }
 
 void ChangePictureHandler::OnJavascriptAllowed() {
-  user_manager::UserManager::Get()->AddObserver(this);
-
+  user_manager_observer_.Add(user_manager::UserManager::Get());
   camera_observer_.Add(CameraPresenceNotifier::GetInstance());
 }
 
 void ChangePictureHandler::OnJavascriptDisallowed() {
-  user_manager::UserManager::Get()->RemoveObserver(this);
-
+  user_manager_observer_.Remove(user_manager::UserManager::Get());
   camera_observer_.Remove(CameraPresenceNotifier::GetInstance());
 }
 
 void ChangePictureHandler::SendDefaultImages() {
   base::ListValue image_urls;
   for (int i = default_user_image::kFirstDefaultImageIndex;
        i < default_user_image::kDefaultImagesCount; ++i) {
     std::unique_ptr<base::DictionaryValue> image_data(
         new base::DictionaryValue);
     image_data->SetString("url", default_user_image::GetDefaultImageUrl(i));
@@ skipping 273 matching lines @@
   Profile* profile = Profile::FromWebUI(web_ui());
   const user_manager::User* user =
       ProfileHelper::Get()->GetUserByProfile(profile);
   if (!user)
     return user_manager::UserManager::Get()->GetActiveUser();
   return user;
 }
 
 }  // namespace settings
 }  // namespace chromeos