Separate ash::test::DisplayManagerTestApi from ash

ash/mus/workspace/workspace_layout_manager_unittest.cc

 // 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.
 
 #include "ash/common/wm/workspace/workspace_layout_manager.h"
 
 #include <string>
 #include <utility>
 
 #include "ash/common/shell_observer.h"
@@ skipping 110 matching lines @@
 
 /*
 TEST_F(WorkspaceLayoutManagerTest, KeepMinimumVisibilityInDisplays) {
   if (!SupportsMultipleDisplays())
     return;
 
   UpdateDisplay("300x400,400x500");
   aura::Window::Windows root_windows = Shell::GetAllRootWindows();
 
   Shell::GetInstance()->display_manager()->SetLayoutForCurrentDisplays(
-      test::CreateDisplayLayout(display::DisplayPlacement::TOP, 0));
+      test::CreateDisplayLayout(display_manager(),
+display::DisplayPlacement::TOP, 0));
   EXPECT_EQ("0,-500 400x500", root_windows[1]->GetBoundsInScreen().ToString());
 
   std::unique_ptr<aura::Window> window1(
       CreateTestWindowInShellWithBounds(gfx::Rect(10, -400, 200, 200)));
   EXPECT_EQ("10,-400 200x200", window1->GetBoundsInScreen().ToString());
 
   // Make sure the caption is visible.
   std::unique_ptr<aura::Window> window2(
       CreateTestWindowInShellWithBounds(gfx::Rect(10, -600, 200, 200)));
   EXPECT_EQ("10,-500 200x200", window2->GetBoundsInScreen().ToString());
@@ skipping 947 matching lines @@
                       occluded_window_bounds.width(),
                       occluded_window_bounds.height()).ToString(),
             window->bounds().ToString());
   HideKeyboard();
   EXPECT_EQ(occluded_window_bounds.ToString(), window->bounds().ToString());
 }
 */
 
 }  // namespace mus
 }  // namespace ash