Allow dynamic enabling/disabling of unified desktop

ash/root_window_controller_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/root_window_controller.h"
 
 #include "ash/display/display_manager.h"
 #include "ash/session/session_state_delegate.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shell.h"
@@ skipping 275 matching lines @@
   EXPECT_EQ(root_windows[0], modal->GetNativeView()->GetRootWindow());
   EXPECT_TRUE(wm::IsActiveWindow(modal->GetNativeView()));
   generator_1st.ClickLeftButton();
   EXPECT_TRUE(wm::IsActiveWindow(modal->GetNativeView()));
 }
 
 // Make sure lock related windows moves.
 TEST_F(RootWindowControllerTest, MoveWindows_LockWindowsInUnified) {
   if (!SupportsMultipleDisplays())
     return;
-  test::DisplayManagerTestApi::EnableUnifiedDesktopForTest();
+  Shell::GetInstance()->display_manager()->SetUnifiedDesktopEnabled(true);
 
   UpdateDisplay("500x500");
   const int kLockScreenWindowId = 1000;
   const int kLockBackgroundWindowId = 1001;
 
   RootWindowController* controller =
       Shell::GetInstance()->GetPrimaryRootWindowController();
 
   aura::Window* lock_container =
       controller->GetContainer(kShellWindowId_LockScreenContainer);
@@ skipping 723 matching lines @@
   keyboard_controller->proxy()->GetKeyboardWindow()->SetBounds(
       gfx::Rect(0, 400, 800, 200));
   EXPECT_EQ("0,400 800x200", keyboard_container->bounds().ToString());
 
   UpdateDisplay("600x800");
   EXPECT_EQ("0,600 600x200", keyboard_container->bounds().ToString());
 }
 
 }  // namespace test
 }  // namespace ash