Cleanup shelf initialization and observation.

ash/shelf/shelf_delegate.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_DELEGATE_H_
 #define ASH_SHELF_SHELF_DELEGATE_H_
 
 #include "ash/ash_export.h"
 #include "ash/shelf/shelf_item_types.h"
 
 namespace ash {
 class Shelf;
 
 // Delegate for the Shelf.
 class ASH_EXPORT ShelfDelegate {
  public:
   // Shelf owns the delegate.
   virtual ~ShelfDelegate() {}
 
   // Callback used to allow delegate to perform initialization actions that
   // depend on the Shelf being in a known state.
   virtual void OnShelfCreated(Shelf* shelf) = 0;
 
   // Callback used to inform the delegate that a specific shelf no longer
   // exists.
   virtual void OnShelfDestroyed(Shelf* shelf) = 0;
 
+  // Called when |shelf|'s alignment changes.
+  virtual void OnShelfAlignmentChanged(Shelf* shelf) = 0;
+
+  // Called when |shelf|'s auto-hide behavior changes.
+  virtual void OnShelfAutoHideBehaviorChanged(Shelf* shelf) = 0;
+
   // Get the shelf ID from an application ID.
   virtual ShelfID GetShelfIDForAppID(const std::string& app_id) = 0;
 
   // Checks whether a mapping exists from the ShelfID |id| to an app id.
   virtual bool HasShelfIDToAppIDMapping(ShelfID id) const = 0;
 
   // Get the application ID for a given shelf ID.
   // |HasShelfIDToAppIDMapping(ShelfID)| should be called first to ensure the
   // ShelfID can be successfully mapped to an app id.
   virtual const std::string& GetAppIDForShelfID(ShelfID id) = 0;
 
   // Pins an app with |app_id| to shelf. A running instance will get pinned.
   // In case there is no running instance a new shelf item is created and
   // pinned.
   virtual void PinAppWithID(const std::string& app_id) = 0;
 
   // Check if the app with |app_id_| is pinned to the shelf.
   virtual bool IsAppPinned(const std::string& app_id) = 0;
 
   // Unpins app item with |app_id|.
   virtual void UnpinAppWithID(const std::string& app_id) = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_DELEGATE_H_