Revert 149869 because it broke ash_unittests on win_aura and linux_chromeos.

ash/desktop_background/desktop_background_view.cc

Index: ash/desktop_background/desktop_background_view.cc
===================================================================
--- ash/desktop_background/desktop_background_view.cc	(revision 149877)
+++ ash/desktop_background/desktop_background_view.cc	(working copy)
@@ -10,6 +10,7 @@
 #include "ash/desktop_background/desktop_background_controller.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
+#include "ash/wm/root_window_layout_manager.h"
 #include "ash/wm/window_animations.h"
 #include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
@@ -30,10 +31,8 @@
 class ShowWallpaperAnimationObserver : public ui::ImplicitAnimationObserver {
  public:
   ShowWallpaperAnimationObserver(aura::RootWindow* root_window,
-                                 int container_id,
                                  views::Widget* desktop_widget)
       : root_window_(root_window),
-        container_id_(container_id),
         desktop_widget_(desktop_widget) {
   }
 
@@ -43,6 +42,11 @@
  private:
   // Overridden from ui::ImplicitAnimationObserver:
   virtual void OnImplicitAnimationsCompleted() OVERRIDE {
+    internal::RootWindowLayoutManager* root_window_layout =
+        static_cast<internal::RootWindowLayoutManager*>(
+            root_window_->layout_manager());
+    root_window_layout->SetBackgroundWidget(desktop_widget_);
+
     ash::Shell::GetInstance()->
         user_wallpaper_delegate()->OnWallpaperAnimationFinished();
 
@@ -50,7 +54,6 @@
   }
 
   aura::RootWindow* root_window_;
-  int container_id_;
   views::Widget* desktop_widget_;
 
   DISALLOW_COPY_AND_ASSIGN(ShowWallpaperAnimationObserver);
@@ -135,8 +138,7 @@
   Shell::GetInstance()->ShowBackgroundMenu(GetWidget(), point);
 }
 
-views::Widget* CreateDesktopBackground(aura::RootWindow* root_window,
-                                       int container_id) {
+void CreateDesktopBackground(aura::RootWindow* root_window) {
   DesktopBackgroundController* controller = ash::Shell::GetInstance()->
       desktop_background_controller();
   views::Widget* desktop_widget = new views::Widget;
@@ -146,7 +148,8 @@
   params.delegate = view;
   if (controller->GetWallpaper().empty())
     params.transparent = true;
-  params.parent = root_window->GetChildById(container_id);
+  params.parent = root_window->GetChildById(
+      ash::internal::kShellWindowId_DesktopBackgroundContainer);
   desktop_widget->Init(params);
   desktop_widget->SetContentsView(view);
   ash::WindowVisibilityAnimationType animation_type =
@@ -160,11 +163,9 @@
       desktop_widget->GetNativeView()->layer()->GetAnimator());
   settings.SetPreemptionStrategy(ui::LayerAnimator::ENQUEUE_NEW_ANIMATION);
   settings.AddObserver(new ShowWallpaperAnimationObserver(root_window,
-                                                          container_id,
                                                           desktop_widget));
   desktop_widget->Show();
   desktop_widget->GetNativeView()->SetName("DesktopBackgroundView");
-  return desktop_widget;
 }
 
 }  // namespace internal