Separate ash::test::DisplayManagerTestApi from ash

ash/screen_util.cc

 // Copyright 2014 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.
 
 #include "ash/screen_util.h"
 
 #include "ash/aura/wm_shelf_aura.h"
 #include "ash/display/display_manager.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
@@ skipping 54 matching lines @@
 // static
 gfx::Rect ScreenUtil::ConvertRectFromScreen(aura::Window* window,
                                             const gfx::Rect& rect) {
   gfx::Point point = rect.origin();
   aura::client::GetScreenPositionClient(window->GetRootWindow())
       ->ConvertPointFromScreen(window, &point);
   return gfx::Rect(point, rect.size());
 }
 
 // static
-const display::Display& ScreenUtil::GetSecondaryDisplay() {
-  DisplayManager* display_manager = GetDisplayManager();
-  CHECK_LE(2U, display_manager->GetNumDisplays());
-  return display_manager->GetDisplayAt(0).id() ==
-                 display::Screen::GetScreen()->GetPrimaryDisplay().id()
-             ? display_manager->GetDisplayAt(1)
-             : display_manager->GetDisplayAt(0);
-}
 
 }  // namespace ash