Cleanup shelf initialization and observation.

ash/shell/shelf_delegate_impl.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_SHELL_SHELF_DELEGATE_IMPL_H_
 #define ASH_SHELL_SHELF_DELEGATE_IMPL_H_
 
 #include "ash/shelf/shelf_delegate.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 
 namespace ash {
 namespace shell {
 
 class ShelfDelegateImpl : public ShelfDelegate {
  public:
   ShelfDelegateImpl();
   ~ShelfDelegateImpl() override;
 
   // ShelfDelegate overrides:
   void OnShelfCreated(Shelf* shelf) override;
   void OnShelfDestroyed(Shelf* shelf) override;
+  void OnShelfAlignmentChanged(Shelf* shelf) override;
+  void OnShelfAutoHideBehaviorChanged(Shelf* shelf) override;
   ShelfID GetShelfIDForAppID(const std::string& app_id) override;
   bool HasShelfIDToAppIDMapping(ShelfID id) const override;
   const std::string& GetAppIDForShelfID(ShelfID id) override;
   void PinAppWithID(const std::string& app_id) override;
   bool IsAppPinned(const std::string& app_id) override;
   void UnpinAppWithID(const std::string& app_id) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ShelfDelegateImpl);
 };
 
 }  // namespace shell
 }  // namespace ash
 
 #endif  // ASH_SHELL_SHELF_DELEGATE_IMPL_H_