Restore to user selected wallpaper after browser crash

chrome/browser/chromeos/background/desktop_background_observer.cc

Index: chrome/browser/chromeos/background/desktop_background_observer.cc
diff --git a/chrome/browser/chromeos/background/desktop_background_observer.cc b/chrome/browser/chromeos/background/desktop_background_observer.cc
index bf464d76792727df7eb0b003f1a54568ec86830e..cce0ede1697fa6bae46e90caeaef066914bc1dc7 100644
--- a/chrome/browser/chromeos/background/desktop_background_observer.cc
+++ b/chrome/browser/chromeos/background/desktop_background_observer.cc
@@ -14,6 +14,36 @@
 
 namespace chromeos {
 
+namespace {
+
+class UserWallpaperDelegate: public ash::UserWallpaperDelegate {
+ public:
+  explicit UserWallpaperDelegate() {
+  }
+
+  virtual ~UserWallpaperDelegate() {
+  }
+
+  virtual const int GetUserWallpaperIndex() OVERRIDE{
+    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;
+  }
+};
+
+}  // namespace
+
+ash::UserWallpaperDelegate* CreateUserWallpaperDelegate() {
+  return new chromeos::UserWallpaperDelegate();
+}
+
 DesktopBackgroundObserver::DesktopBackgroundObserver() {
   registrar_.Add(
       this,
@@ -24,25 +54,13 @@ DesktopBackgroundObserver::DesktopBackgroundObserver() {
 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());
+          OnUserLoginOrSwitchToImageMode();
       break;
     }
     default: