mash: Move ShelfModel* to ash/public/cpp.

ash/public/cpp/shelf_model_observer.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_SHELF_SHELF_MODEL_OBSERVER_H_
-#define ASH_SHELF_SHELF_MODEL_OBSERVER_H_
+#ifndef ASH_PUBLIC_CPP_SHELF_MODEL_OBSERVER_H_
+#define ASH_PUBLIC_CPP_SHELF_MODEL_OBSERVER_H_
 
-#include "ash/ash_export.h"
+#include "ash/public/cpp/ash_public_export.h"
 #include "ash/public/cpp/shelf_types.h"
 
 namespace ash {
 
 struct ShelfItem;
 class ShelfItemDelegate;
 
-// TODO(msw): Move this to ash/public/cpp and use ASH_PUBLIC_EXPORT.
-class ASH_EXPORT ShelfModelObserver {
+// An observer interface for shelf item and delegate changes in ShelfModel.
+class ASH_PUBLIC_EXPORT ShelfModelObserver {
  public:
   // Invoked after an item has been added to the model.
   virtual void ShelfItemAdded(int index) = 0;
 
   // Invoked after an item has been removed from the model. |index| is the index
   // the item was at before removal, |old_item| is the item before removal.
   virtual void ShelfItemRemoved(int index, const ShelfItem& old_item) = 0;
 
   // Invoked after an item has been moved. See ShelfModel::Move() for details
   // of the arguments.
   virtual void ShelfItemMoved(int start_index, int target_index) = 0;
 
   // Invoked after an item changes. |old_item| is the item before the change.
   virtual void ShelfItemChanged(int index, const ShelfItem& old_item) = 0;
 
   // Invoked after a delegate changes. |delegate| is the new value.
   virtual void ShelfItemDelegateChanged(const ShelfID& id,
                                         ShelfItemDelegate* delegate) = 0;
 
  protected:
   virtual ~ShelfModelObserver() {}
 };
 
 }  // namespace ash
 
-#endif  // ASH_SHELF_SHELF_MODEL_OBSERVER_H_
+#endif  // ASH_PUBLIC_CPP_SHELF_MODEL_OBSERVER_H_