ash: Cleanup class/struct forward declarations

ash/display/window_tree_host_manager.h

 // Copyright (c) 2012 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_DISPLAY_DISPLAY_CONTROLLER_H_
 #define ASH_DISPLAY_DISPLAY_CONTROLLER_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 12 matching lines @@
 #include "ui/base/ime/input_method.h"
 #include "ui/base/ime/input_method_delegate.h"
 #include "ui/display/display_observer.h"
 #include "ui/display/manager/display_manager.h"
 #include "ui/gfx/geometry/point.h"
 
 namespace aura {
 class WindowTreeHost;
 }
 
-namespace base {
-class Value;
-template <typename T>
-class JSONValueConverter;
-}
-
 namespace gfx {
 class Insets;
 }
 
 namespace ash {
 class AshWindowTreeHost;
 struct AshWindowTreeHostInitParams;
 class CursorWindowController;
 class FocusActivationStore;
 class InputMethodEventHandler;
@@ skipping 174 matching lines @@
   int64_t cursor_display_id_for_restore_;
 
   base::WeakPtrFactory<WindowTreeHostManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHostManager);
 };
 
 }  // namespace ash
 
 #endif  // ASH_DISPLAY_DISPLAY_CONTROLLER_H_