Revert of AppListController refactoring part 3: Switching over to use AppListShower in Ash.

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index 46548742f7fd9c2f528090b47c2dd9f35d4b5b8e..f6f3839ce9801c64db1964345ff2d9da275d2774 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -248,6 +248,12 @@
   // Returns app list target visibility.
   bool GetAppListTargetVisibility() const;
 
+  // Returns app list window or NULL if it is not visible.
+  aura::Window* GetAppListWindow();
+
+  // Returns app list view if one exists, or NULL otherwise.
+  app_list::AppListView* GetAppListView();
+
   // Returns true if a system-modal dialog window is currently open.
   bool IsSystemModalWindowOpen() const;
 
@@ -662,6 +668,8 @@
 
   std::unique_ptr<ShelfModel> shelf_model_;
   std::unique_ptr<WindowPositioner> window_positioner_;
+
+  std::unique_ptr<AppListController> app_list_controller_;
 
   std::unique_ptr<DragDropController> drag_drop_controller_;
   std::unique_ptr<ResizeShadowController> resize_shadow_controller_;
@@ -685,7 +693,6 @@
       partial_magnification_controller_;
   std::unique_ptr<AutoclickController> autoclick_controller_;
   std::unique_ptr<aura::client::FocusClient> focus_client_;
-
   aura::client::ActivationClient* activation_client_;
   std::unique_ptr<PartialScreenshotController> partial_screenshot_controller_;