ash: Reorder shutdown of ShelfLayoutManager and StatusAreaWidget

ash/shelf/shelf_tooltip_manager.cc

Index: ash/shelf/shelf_tooltip_manager.cc
diff --git a/ash/shelf/shelf_tooltip_manager.cc b/ash/shelf/shelf_tooltip_manager.cc
index 3f9bbed3ae24c7f216c18382cc1eb35a9da1728d..de34fb680b2273d54ce210ba35d9b071206551cc 100644
--- a/ash/shelf/shelf_tooltip_manager.cc
+++ b/ash/shelf/shelf_tooltip_manager.cc
@@ -101,7 +101,7 @@ ShelfTooltipManager::ShelfTooltipManager(ShelfView* shelf_view)
       weak_factory_(this) {}
 
 ShelfTooltipManager::~ShelfTooltipManager() {
-  WillDeleteShelf();
+  WillDeleteShelfLayoutManager();
 
   Shell::GetInstance()->RemovePointerWatcher(this);
 
@@ -226,7 +226,7 @@ void ShelfTooltipManager::OnWindowDestroying(aura::Window* window) {
   }
 }
 
-void ShelfTooltipManager::WillDeleteShelf() {
+void ShelfTooltipManager::WillDeleteShelfLayoutManager() {
   if (shelf_layout_manager_)
     shelf_layout_manager_->RemoveObserver(this);
   shelf_layout_manager_ = nullptr;