Delay wallpaper load by 2 * average wallpaper load time.

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
index ba1809b38fc5bf774c990638225df903bc81ce4c..07c2f3fa20e41f3bcef0dc17366322ebfb4ae838 100644
--- a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
@@ -422,9 +422,12 @@ SigninScreenHandler::SigninScreenHandler(
   registrar_.Add(this,
                  chrome::NOTIFICATION_AUTH_CANCELLED,
                  content::NotificationService::AllSources());
+
+  WallpaperManager::Get()->AddObserver(this);
 }
 
 SigninScreenHandler::~SigninScreenHandler() {
+  WallpaperManager::Get()->RemoveObserver(this);
   weak_factory_.InvalidateWeakPtrs();
   SystemKeyEventListener* key_event_listener =
       SystemKeyEventListener::GetInstance();
@@ -1291,6 +1294,11 @@ void SigninScreenHandler::HandleLoadWallpaper(const std::string& email) {
     delegate_->LoadWallpaper(email);
 }
 
+void SigninScreenHandler::OnWallpaperAnimationFinished(
+    const std::string& email) {
+  CallJS("login.AccountPickerScreen.onWallpaperLoaded", email);
+}
+
 void SigninScreenHandler::HandleRebootSystem() {
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->RequestRestart();
 }