Fix login visual hitch on chromebook

chrome/browser/chromeos/login/wallpaper_manager.cc

Index: chrome/browser/chromeos/login/wallpaper_manager.cc
diff --git a/chrome/browser/chromeos/login/wallpaper_manager.cc b/chrome/browser/chromeos/login/wallpaper_manager.cc
index 4d816268b438a443befa612a408d080c71b33620..f1e7cbf00d42d6df1c11edda807f26be69426775 100644
--- a/chrome/browser/chromeos/login/wallpaper_manager.cc
+++ b/chrome/browser/chromeos/login/wallpaper_manager.cc
@@ -119,6 +119,22 @@ WallpaperManager::WallpaperManager()
       GetSequencedTaskRunnerWithShutdownBehavior(
           sequence_token_,
           base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN);
+  DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(this);
+  system::TimezoneSettings::GetInstance()->AddObserver(this);
+  CrosSettings::Get()->AddSettingsObserver(kAccountsPrefShowUserNamesOnSignIn,
+                                           this);
+}
+
+WallpaperManager::~WallpaperManager() {
+  ClearObsoleteWallpaperPrefs();

[Nikita (slow), 2013/01/22 11:30:54]

DCHECK that shutdown has been called.

[bshe, 2013/01/22 15:36:26]

Done.

+  weak_factory_.InvalidateWeakPtrs();
+}
+
+void WallpaperManager::Shutdown() {
+  DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(this);
+  system::TimezoneSettings::GetInstance()->RemoveObserver(this);
+  CrosSettings::Get()->RemoveSettingsObserver(
+      kAccountsPrefShowUserNamesOnSignIn, this);
 }
 
 // static
@@ -128,11 +144,6 @@ void WallpaperManager::RegisterPrefs(PrefServiceSimple* local_state) {
   local_state->RegisterDictionaryPref(kUserWallpapersProperties);
 }
 
-void WallpaperManager::AddObservers() {
-  DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(this);
-  system::TimezoneSettings::GetInstance()->AddObserver(this);
-}
-
 void WallpaperManager::EnsureLoggedInUserWallpaperLoaded() {
   // Some browser tests do not have a shell instance. As no wallpaper is needed
   // in these tests anyway, avoid loading one, preventing crashes and speeding
@@ -267,6 +278,13 @@ void WallpaperManager::Observe(int type,
       }
       break;
     }
+    case chrome::NOTIFICATION_SYSTEM_SETTING_CHANGED: {
+      if (*content::Details<const std::string>(details).ptr() ==
+          kAccountsPrefShowUserNamesOnSignIn) {
+        InitializeRegisteredDeviceWallpaper();
+      }
+      break;
+    }
     default:
       NOTREACHED() << "Unexpected notification " << type;
   }
@@ -553,13 +571,6 @@ void WallpaperManager::UpdateWallpaper() {
 
 // WallpaperManager, private: --------------------------------------------------
 
-WallpaperManager::~WallpaperManager() {
-  ClearObsoleteWallpaperPrefs();
-  DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(this);
-  system::TimezoneSettings::GetInstance()->RemoveObserver(this);
-  weak_factory_.InvalidateWeakPtrs();
-}
-
 void WallpaperManager::BatchUpdateWallpaper() {
   NOTIMPLEMENTED();
 }
@@ -650,12 +661,9 @@ void WallpaperManager::DeleteUserWallpapers(const std::string& email) {
 }
 
 void WallpaperManager::InitializeRegisteredDeviceWallpaper() {
-  if (CrosSettingsProvider::TEMPORARILY_UNTRUSTED ==
-      CrosSettings::Get()->PrepareTrustedValues(
-          base::Bind(&WallpaperManager::InitializeRegisteredDeviceWallpaper,
-                     base::Unretained(this)))) {
+  if (UserManager::Get()->IsUserLoggedIn())
     return;
-  }
+
   bool disable_boot_animation = CommandLine::ForCurrentProcess()->
       HasSwitch(switches::kDisableBootAnimation);
   bool show_users = true;