Make cancelling of app list correctly clean up folder UI.

ui/app_list/views/apps_grid_view.h

Index: ui/app_list/views/apps_grid_view.h
diff --git a/ui/app_list/views/apps_grid_view.h b/ui/app_list/views/apps_grid_view.h
index 536a835b8df038d20068225856d78de621ed07b9..22d8bb19ed97f35cc4101eb54222b891672bceeb 100644
--- a/ui/app_list/views/apps_grid_view.h
+++ b/ui/app_list/views/apps_grid_view.h
@@ -51,6 +51,7 @@ class AppsGridViewTestApi;
 class ApplicationDragAndDropHost;
 class AppListItemView;
 class AppsGridViewDelegate;
+class AppsGridViewFolderDelegate;
 class PageSwitcher;
 class PaginationModel;
 
@@ -196,7 +197,9 @@ class APP_LIST_EXPORT AppsGridView : public views::View,
     return forward_events_to_drag_and_drop_host_;
   }
 
-  void set_is_root_level(bool value) { is_root_level_ = value; }
+  void set_folder_delegate(AppsGridViewFolderDelegate* folder_delegate) {
+    folder_delegate_ = folder_delegate;
+  }
 
   AppListItemView* activated_item_view() const {
     return activated_item_view_;
@@ -427,7 +430,7 @@ class APP_LIST_EXPORT AppsGridView : public views::View,
 
   // Returns true if drag event is happening in the hidden AppsGridView of the
   // folder during reparenting a folder item.
-  bool IsDraggingForReprentInHiddenGridView() const;
+  bool IsDraggingForReparentInHiddenGridView() const;
 
   // Returns the target icon bounds for |drag_item_view| to fly back
   // to its parent |folder_item_view| in animation.
@@ -440,6 +443,10 @@ class APP_LIST_EXPORT AppsGridView : public views::View,
   AppListModel* model_;  // Owned by AppListView.
   AppListItemList* item_list_;  // Not owned.
   AppsGridViewDelegate* delegate_;
+
+  // This can be NULL. Only grid views inside folders have a folder delegate.
+  AppsGridViewFolderDelegate* folder_delegate_;
+
   PaginationModel* pagination_model_;  // Owned by AppListController.
   PageSwitcher* page_switcher_view_;  // Owned by views hierarchy.
 
@@ -514,9 +521,6 @@ class APP_LIST_EXPORT AppsGridView : public views::View,
 
   views::BoundsAnimator bounds_animator_;
 
-  // If true, AppsGridView is rending items at the root level of the app list.
-  bool is_root_level_;
-
   // The most recent activated item view.
   AppListItemView* activated_item_view_;