Restore to user selected wallpaper after browser crash

chrome/browser/chromeos/background/desktop_background_observer.cc

 // Copyright (c) 2012 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/background/desktop_background_observer.h"
 
 #include "ash/shell.h"
 #include "ash/desktop_background/desktop_background_controller.h"
 #include "ash/desktop_background/desktop_background_resources.h"
 #include "base/logging.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "content/public/browser/notification_service.h"
 
 namespace chromeos {
 
+namespace {
+
+class UserWallpaperDelegate: public ash::UserWallpaperDelegate {
+ public:
+  UserWallpaperDelegate() {
+  }
+
+  virtual ~UserWallpaperDelegate() {
+  }
+
+  virtual const int GetUserWallpaperIndex() OVERRIDE {
+    chromeos::UserManager* user_manager = chromeos::UserManager::Get();
+    // If at login screen or logged in as a guest/incognito user, then use the
+    // default wallpaper.
+    if (user_manager->IsLoggedInAsGuest() || !user_manager->IsUserLoggedIn())
+      return ash::GetDefaultWallpaperIndex();
+
+    const chromeos::User& user = user_manager->GetLoggedInUser();
+    DCHECK(!user.email().empty());
+    int index = user_manager->GetUserWallpaper(user.email());
+    DCHECK(index >=0 && index < ash::GetWallpaperCount());
+    return index;
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(UserWallpaperDelegate);
+};
+
+}  // namespace
+
+ash::UserWallpaperDelegate* CreateUserWallpaperDelegate() {
+  return new chromeos::UserWallpaperDelegate();
+}
+
 DesktopBackgroundObserver::DesktopBackgroundObserver() {
   registrar_.Add(
       this,
       chrome::NOTIFICATION_LOGIN_USER_CHANGED,
       content::NotificationService::AllSources());
 }
 
 DesktopBackgroundObserver::~DesktopBackgroundObserver() {
 }
 
-int DesktopBackgroundObserver::GetUserWallpaperIndex() {
-  chromeos::UserManager* user_manager = chromeos::UserManager::Get();
-  // Guest/incognito user do not have an email address.
-  if (user_manager->IsLoggedInAsGuest())
-    return ash::GetDefaultWallpaperIndex();
-  const chromeos::User& user = user_manager->GetLoggedInUser();
-  DCHECK(!user.email().empty());
-  int index = user_manager->GetUserWallpaper(user.email());
-  DCHECK(index >=0 && index < ash::GetWallpaperCount());
-  return index;
-}
-
 void DesktopBackgroundObserver::Observe(int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   switch (type) {
     case chrome::NOTIFICATION_LOGIN_USER_CHANGED: {
       ash::Shell::GetInstance()->desktop_background_controller()->
-          OnDesktopBackgroundChanged(GetUserWallpaperIndex());
+          OnDesktopBackgroundChanged();
       break;
     }
     default:
       NOTREACHED();
   }
 }
 
 }  // namespace chromeos