ui: Cleanup class/struct forward declarations

ui/app_list/presenter/app_list_presenter_impl.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 UI_APP_LIST_PRESENTER_APP_LIST_PRESENTER_IMPL_H_
 #define UI_APP_LIST_PRESENTER_APP_LIST_PRESENTER_IMPL_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "ui/app_list/pagination_model_observer.h"
 #include "ui/app_list/presenter/app_list_presenter.h"
 #include "ui/app_list/presenter/app_list_presenter_delegate.h"
 #include "ui/aura/client/focus_change_observer.h"
 #include "ui/aura/window_observer.h"
 #include "ui/compositor/layer_animation_observer.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/views/widget/widget_observer.h"
 
 namespace app_list {
 class AppListView;
 class AppListViewDelegate;
 class AppListPresenterDelegateFactory;
 
 namespace test {
 class AppListPresenterImplTestApi;
 }
 
-class AppListPresenterImplTest;
 class AppListViewDelegate;
 
 // Manages app list UI. Creates AppListView and schedules showing/hiding
 // animation. While the UI is visible, it monitors things such as app list
 // activation state to auto dismiss the UI. Delegates the responsibility
 // for laying out the app list UI to ash::AppListLayoutDelegate.
 class APP_LIST_PRESENTER_EXPORT AppListPresenterImpl
     : public AppListPresenter,
       public aura::client::FocusChangeObserver,
       public aura::WindowObserver,
@@ skipping 71 matching lines @@
 
   // Whether should schedule snap back animation.
   bool should_snap_back_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(AppListPresenterImpl);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_PRESENTER_APP_LIST_PRESENTER_IMPL_H_