Relocate display_manager from ash to ui

ash/screen_util_unittest.cc

Index: ash/screen_util_unittest.cc
diff --git a/ash/screen_util_unittest.cc b/ash/screen_util_unittest.cc
index 77d33c330a223c1350fc6abbf0ce878174817f46..13c23631bddb76e10512eece077135475e7665e2 100644
--- a/ash/screen_util_unittest.cc
+++ b/ash/screen_util_unittest.cc
@@ -7,14 +7,13 @@
 #include "ash/common/wm/wm_screen_util.h"
 #include "ash/common/wm_lookup.h"
 #include "ash/common/wm_window.h"
-#include "ash/display/display_manager.h"
 #include "ash/shell.h"
 #include "ash/test/ash_md_test_base.h"
-#include "ash/test/display_manager_test_api.h"
 #include "ash/wm/window_util.h"
 #include "ui/aura/env.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
+#include "ui/display/manager/display_manager.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_delegate.h"
 
@@ -126,9 +125,8 @@ TEST_P(ScreenUtilTest, ConvertRect) {
 TEST_P(ScreenUtilTest, ShelfDisplayBoundsInUnifiedDesktop) {
   if (!SupportsMultipleDisplays())
     return;
-  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
 
-  display_manager->SetUnifiedDesktopEnabled(true);
+  display_manager()->SetUnifiedDesktopEnabled(true);
 
   views::Widget* widget = views::Widget::CreateWindowWithContextAndBounds(
       NULL, CurrentContext(), gfx::Rect(10, 10, 100, 100));