Fix white flash when user sings out and wallpaper animation regression

ash/desktop_background/desktop_background_widget_controller.cc

Index: ash/desktop_background/desktop_background_widget_controller.cc
diff --git a/ash/desktop_background/desktop_background_widget_controller.cc b/ash/desktop_background/desktop_background_widget_controller.cc
index 6e6d799cb154400d6be68f0911d2d81a9936088b..1d0f5fa9066c1ff5100c17e0e5018a565b32e584 100644
--- a/ash/desktop_background/desktop_background_widget_controller.cc
+++ b/ash/desktop_background/desktop_background_widget_controller.cc
@@ -8,12 +8,14 @@
 #include "ui/views/widget/widget.h"
 
 DECLARE_WINDOW_PROPERTY_TYPE(ash::internal::DesktopBackgroundWidgetController*);
+DECLARE_WINDOW_PROPERTY_TYPE(ash::internal::ComponentWrapper*);
 
 namespace ash {
 namespace internal {
 
 DEFINE_OWNED_WINDOW_PROPERTY_KEY(DesktopBackgroundWidgetController,
                                  kWindowDesktopComponent, NULL);
+DEFINE_OWNED_WINDOW_PROPERTY_KEY(ComponentWrapper, kComponentWrapper, NULL);
 
 DesktopBackgroundWidgetController::DesktopBackgroundWidgetController(
     views::Widget* widget) : widget_(widget) {
@@ -39,7 +41,6 @@ void DesktopBackgroundWidgetController::SetBounds(gfx::Rect bounds) {
     layer_->SetBounds(bounds);
 }
 
-
 void DesktopBackgroundWidgetController::Reparent(aura::RootWindow* root_window,
                                                  int src_container,
                                                  int dest_container) {
@@ -53,5 +54,9 @@ void DesktopBackgroundWidgetController::Reparent(aura::RootWindow* root_window,
   }
 }
 
+ComponentWrapper::ComponentWrapper(
+    DesktopBackgroundWidgetController* component) : component_(component) {
+}
+
 }  // namespace internal
 }  // namespace ash