Makes workspace 2 show an alternate background (system background)

ash/root_window_controller.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 "ash/root_window_controller.h"
 
 #include <vector>
 
 #include "ash/desktop_background/desktop_background_widget_controller.h"
 #include "ash/display/display_controller.h"
@@ skipping 133 matching lines @@
       root_window);
   aura::Window* lock_screen_related_containers = CreateContainer(
       internal::kShellWindowId_LockScreenRelatedContainersContainer,
       "LockScreenRelatedContainersContainer",
       root_window);
 
   CreateContainer(internal::kShellWindowId_UnparentedControlContainer,
                   "UnparentedControlContainer",
                   non_lock_screen_containers);
 
+  CreateContainer(internal::kShellWindowId_SystemBackgroundContainer,
+                  "SystemBackgroundContainer", non_lock_screen_containers);
+
   aura::Window* desktop_background_containers = CreateContainer(
       internal::kShellWindowId_DesktopBackgroundContainer,
       "DesktopBackgroundContainer",
       non_lock_screen_containers);
   SetChildWindowVisibilityChangesAnimated(desktop_background_containers);
 
   aura::Window* default_container = CreateContainer(
       internal::kShellWindowId_DefaultContainer,
       "DefaultContainer",
       non_lock_screen_containers);
@@ skipping 199 matching lines @@
   // Restore focused or active window if it's still alive.
   if (focused && tracker.Contains(focused) && dst->Contains(focused)) {
     dst->GetFocusManager()->SetFocusedWindow(focused, NULL);
   } else if (active && tracker.Contains(active) && dst->Contains(active)) {
     activation_client->ActivateWindow(active);
   }
 }
 
 }  // namespace internal
 }  // namespace ash