Move to DesktopScreenX11::UpdateDeviceScaleFactor to TestApi

ui/views/test/desktop_screen_x11_test_api.h

+// Copyright 2015 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_VIEWS_TEST_DESKTOP_SCREEN_X11_TEST_API_H_
+#define UI_VIEWS_TEST_DESKTOP_SCREEN_X11_TEST_API_H_
+
+#include "base/macros.h"
+
+namespace views {
+namespace test {
+
+class DesktopScreenX11TestApi {
+ public:
+  // Updates the displays. Typically used to reflect customized device
+  // scale factor in displays.
+  static void UpdateDisplays();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DesktopScreenX11TestApi);
+};
+
+}  // namespace test
+}  // namespace views
+
+#endif  // UI_VIEWS_TEST_DESKTOP_SCREEN_X11_TEST_API_H_