Use Ash's ShelfWindowWatcher for app panel windows.

ash/common/shelf/shelf_window_watcher.h

 // Copyright 2013 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 ASH_COMMON_SHELF_SHELF_WINDOW_WATCHER_H_
 #define ASH_COMMON_SHELF_SHELF_WINDOW_WATCHER_H_
 
+#include <set>
+
 #include "ash/common/wm_activation_observer.h"
 #include "ash/common/wm_window_observer.h"
 #include "base/macros.h"
 #include "base/scoped_observer.h"
 #include "ui/display/display_observer.h"
 
 namespace ash {
 
 class ShelfModel;
 class WmWindow;
 
 // ShelfWindowWatcher creates and handles a ShelfItem for windows in the default
-// container that have a valid ShelfItemType property (e.g. the task manager
-// dialog or the OS settings window). It adds the ShelfItem when the window is
-// added to the default container and maintains it until the window is closed,
-// even if the window is transiently reparented (e.g. during a drag).
+// container and panels in the panel container that have a valid ShelfItemType
+// property (e.g. the task manager dialog or the OS settings window). It adds
+// the ShelfItem when the window is added to the default container and maintains
+// it until the window is closed, even if the window is transiently reparented
+// (e.g. during a drag).
 class ShelfWindowWatcher : public WmActivationObserver,
                            public display::DisplayObserver {
  public:
   explicit ShelfWindowWatcher(ShelfModel* model);
   ~ShelfWindowWatcher() override;
 
  private:
   // Observes for windows being added to a root window's default container.
   class ContainerWindowObserver : public WmWindowObserver {
    public:
@@ skipping 28 matching lines @@
 
     DISALLOW_COPY_AND_ASSIGN(UserWindowObserver);
   };
 
   // Creates a ShelfItem for |window|.
   void AddShelfItem(WmWindow* window);
 
   // Removes a ShelfItem for |window|.
   void RemoveShelfItem(WmWindow* window);
 
-  // Updates the status of ShelfItem for |window|.
-  void UpdateShelfItemStatus(WmWindow* window, bool is_active);
-
-  // Returns the index of ShelfItem associated with |window|.
+  // Returns the index of ShelfItem associated with |window|, or -1 if none.
   int GetShelfItemIndexForWindow(WmWindow* window) const;
 
   // Cleans up observers on |container|.
   void OnContainerWindowDestroying(WmWindow* container);
 
   // Adds a shelf item for new windows added to the default container that have
   // a valid ShelfItemType property value.
   void OnUserWindowAdded(WmWindow* window);
 
   // Adds, updates or removes the shelf item based on a property change.
@@ skipping 13 matching lines @@
                                uint32_t metrics) override;
 
   ShelfModel* model_;
 
   ContainerWindowObserver container_window_observer_;
   UserWindowObserver user_window_observer_;
 
   ScopedObserver<WmWindow, ContainerWindowObserver> observed_container_windows_;
   ScopedObserver<WmWindow, UserWindowObserver> observed_user_windows_;
 
+  // The set of windows with shelf items managed by this ShelfWindowWatcher.
+  std::set<WmWindow*> user_windows_with_items_;
+
   DISALLOW_COPY_AND_ASSIGN(ShelfWindowWatcher);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SHELF_SHELF_WINDOW_WATCHER_H_