Revert 154611 - "Forget about DesktopBackgroundView if it was deleted"

ash/desktop_background/desktop_background_controller.cc

Index: ash/desktop_background/desktop_background_controller.cc
diff --git a/ash/desktop_background/desktop_background_controller.cc b/ash/desktop_background/desktop_background_controller.cc
index bdbad059050002aff5d767ed9243a0b0d30f8769..0bd8b3542efdffc1fbf6f4ec800ef6d77c570ab8 100644
--- a/ash/desktop_background/desktop_background_controller.cc
+++ b/ash/desktop_background/desktop_background_controller.cc
@@ -246,16 +246,6 @@ void DesktopBackgroundController::MoveDesktopToLockedContainer() {
                             GetBackgroundContainerId(true));
 }
 
-void DesktopBackgroundController::CleanupView(aura::RootWindow* root_window) {
-  internal::ComponentWrapper *wrapper;
-  wrapper = root_window->GetProperty(internal::kComponentWrapper);
-  if (NULL == wrapper)
-    return;
-  if (wrapper->GetComponent(false))
-    wrapper->GetComponent(false)->CleanupWidget();
-}
-
-
 void DesktopBackgroundController::MoveDesktopToUnlockedContainer() {
   if (!locked_)
     return;