Move display preference code from ash/display/ to ui/display/manager/.

ash/display/json_converter.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_DISPLAY_JSON_CONVERTER_H_
-#define ASH_DISPLAY_JSON_CONVERTER_H_
-
-#include "ash/ash_export.h"
-
-namespace base {
-class Value;
-}
-
-namespace display {
-class DisplayLayout;
-}
-
-namespace ash {
-
-ASH_EXPORT bool JsonToDisplayLayout(const base::Value& value,
-                                    display::DisplayLayout* layout);
-
-ASH_EXPORT bool DisplayLayoutToJson(const display::DisplayLayout& layout,
-                                    base::Value* value);
-
-}  // namespace ash
-
-#endif  // ASH_DISPLAY_JSON_CONVERTER_H_