mash: Remove WorkspaceLayoutManagerDelegate.

ash/common/wm/workspace/workspace_layout_manager_delegate.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_COMMON_WM_WORKSPACE_WORKSPACE_LAYOUT_MANAGER_DELEGATE_H_
-#define ASH_COMMON_WM_WORKSPACE_WORKSPACE_LAYOUT_MANAGER_DELEGATE_H_
-
-#include "ash/ash_export.h"
-
-namespace ash {
-namespace wm {
-
-class ASH_EXPORT WorkspaceLayoutManagerDelegate {
- public:
-  virtual ~WorkspaceLayoutManagerDelegate() {}
-
-  // Called when the visibility of the shelf needs to be updated.
-  // TODO(jamescook): Eliminate this and use WmShelf directly.
-  virtual void UpdateShelfVisibility() = 0;
-
-  // Called when the fullscreen state has changed to |is_fullscreen|.
-  virtual void OnFullscreenStateChanged(bool is_fullscreen) = 0;
-};
-
-}  // namespace wm
-}  // namespace ash
-
-#endif  // ASH_COMMON_WM_WORKSPACE_WORKSPACE_LAYOUT_MANAGER_DELEGATE_H_