Reland - cros: Add CHECK for screen unlock problem

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 a6b41b22ad28273444f49bef2072d496fbc4ed09..f5ef02bd97aeb01550f5f3f5a7d89413e621b775 100644
--- a/chrome/browser/chromeos/login/wallpaper_manager.cc
+++ b/chrome/browser/chromeos/login/wallpaper_manager.cc
@@ -270,8 +270,12 @@ void WallpaperManager::InitializeWallpaper() {
     WizardController::SetZeroDelays();
 
   // Zero delays is also set in autotests.
-  if (WizardController::IsZeroDelayEnabled())
+  if (WizardController::IsZeroDelayEnabled()) {
+    // Ensure tests have some sort of wallpaper.
+    ash::Shell::GetInstance()->desktop_background_controller()->
+        CreateEmptyWallpaper();
     return;
+  }
 
   bool disable_new_oobe = CommandLine::ForCurrentProcess()->
       HasSwitch(switches::kDisableNewOobe);