Make cancelling of app list correctly clean up folder UI.

ui/app_list/views/apps_grid_view_folder_delegate.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_APP_LIST_VIEWS_APPS_GRID_VIEW_FOLDER_DELEGATE_H_
+#define UI_APP_LIST_VIEWS_APPS_GRID_VIEW_FOLDER_DELEGATE_H_
+
+#include "ui/app_list/app_list_export.h"
+#include "ui/app_list/views/apps_grid_view.h"
+
+namespace gfx {
+class Point;
+}
+
+namespace ui {
+class LocatedEvent;
+}
+
+namespace app_list {
+
+class AppListItemView;
+
+class APP_LIST_EXPORT AppsGridViewFolderDelegate {

[tapted, 2014/03/26 02:53:54]

all classes in headers should have a class comment.
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Class_Comments

[calamity, 2014/03/27 05:14:44]

Done.

+ public:
+  // Updates the folder view background to show or hide folder container ink
+  // bubble.
+  virtual void UpdateFolderViewBackground(bool show_bubble) = 0;
+
+  // Called when a folder item is dragged out of the folder to be re-parented.
+  // |original_drag_view| is the |drag_view_| inside the folder's grid view.
+  // |drag_point_in_folder_grid| is the last drag point in coordinate of the
+  // AppsGridView inside the folder.
+  virtual void ReparentItem(AppListItemView* original_drag_view,
+                            const gfx::Point& drag_point_in_folder_grid) = 0;
+
+  // Dispatches drag event from the hidden grid view to the root level grid view
+  // for re-parenting a folder item.
+  virtual void DispatchDragEventForReparent(AppsGridView::Pointer pointer,
+                                            const ui::LocatedEvent& event) = 0;
+
+  // Dispatches EndDrag event from the hidden grid view to the root level grid
+  // view for reparenting a folder item.
+  // |events_forwarded_to_drag_drop_host|: True if the dragged item is dropped
+  // to the drag_drop_host, eg. dropped on shelf.
+  virtual void DispatchEndDragEventForReparent(
+      bool events_forwarded_to_drag_drop_host) = 0;
+
+  // Returns true if |point| falls outside of the folder container ink bubble.
+  virtual bool IsPointOutsideOfFolderBoundary(const gfx::Point& point) = 0;
+
+ protected:
+  virtual ~AppsGridViewFolderDelegate() {}
+};
+
+}  // namespace app_list
+
+#endif  // UI_APP_LIST_VIEWS_APPS_GRID_VIEW_FOLDER_DELEGATE_H_