ash: Remove ShelfModel id conversion functions.

ash/shelf/shelf_controller.h

 // Copyright 2016 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_CONTROLLER_H_
 #define ASH_SHELF_SHELF_CONTROLLER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 13 matching lines @@
 class ShelfController : public mojom::ShelfController {
  public:
   ShelfController();
   ~ShelfController() override;
 
   // Binds the mojom::ShelfController interface request to this object.
   void BindRequest(mojom::ShelfControllerRequest request);
 
   ShelfModel* model() { return &model_; }
 
-  const std::map<std::string, ShelfID>& app_id_to_shelf_id() {
-    return app_id_to_shelf_id_;
-  }
-
-  const std::map<ShelfID, std::string>& shelf_id_to_app_id() {
-    return shelf_id_to_app_id_;
-  }
-
   // Functions used to notify mojom::ShelfObserver instances of changes.
   void NotifyShelfCreated(WmShelf* shelf);
   void NotifyShelfAlignmentChanged(WmShelf* shelf);
   void NotifyShelfAutoHideBehaviorChanged(WmShelf* shelf);
 
   // mojom::Shelf:
   void AddObserver(mojom::ShelfObserverAssociatedPtrInfo observer) override;
   void SetAlignment(ShelfAlignment alignment, int64_t display_id) override;
   void SetAutoHideBehavior(ShelfAutoHideBehavior auto_hide,
                            int64_t display_id) override;
   void PinItem(const ShelfItem& item,
                mojom::ShelfItemDelegateAssociatedPtrInfo delegate) override;
   void UnpinItem(const std::string& app_id) override;
   void SetItemImage(const std::string& app_id, const SkBitmap& image) override;
 
  private:
   // The shelf model shared by all shelf instances.
   ShelfModel model_;
 
   // Bindings for the ShelfController interface.
   mojo::BindingSet<mojom::ShelfController> bindings_;
 
   // The set of shelf observers notified about shelf state and settings changes.
   mojo::AssociatedInterfacePtrSet<mojom::ShelfObserver> observers_;
 
-  // Mappings between application and shelf ids.
-  std::map<std::string, ShelfID> app_id_to_shelf_id_;
-  std::map<ShelfID, std::string> shelf_id_to_app_id_;
-
   DISALLOW_COPY_AND_ASSIGN(ShelfController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_CONTROLLER_H_