mash: Move SystemTrayDelegate ownership to WmShell

ash/content/display/screen_orientation_controller_chromeos_unittest.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/display/screen_orientation_controller_chromeos.h"
 
 #include <memory>
 #include <vector>
 
 #include "ash/ash_switches.h"
+#include "ash/common/wm_shell.h"

[msw, 2016/06/10 20:48:10]

nit: remove

 #include "ash/content/shell_content_state.h"
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/ash_test_helper.h"
 #include "ash/test/content/test_shell_content_state.h"
 #include "ash/test/display_manager_test_api.h"
 #include "ash/test/test_shell_delegate.h"
 #include "ash/test/test_system_tray_delegate.h"
@@ skipping 388 matching lines @@
   TriggerLidUpdate(gravity);
   EXPECT_EQ(display::Display::ROTATE_90, GetCurrentInternalDisplayRotation());
 }
 
 // The TrayDisplay class that is responsible for adding/updating MessageCenter
 // notifications is only added to the SystemTray on ChromeOS.
 // Tests that the screen rotation notifications are suppressed when
 // triggered by the accelerometer.
 TEST_F(ScreenOrientationControllerTest, BlockRotationNotifications) {
   EnableMaximizeMode(true);
-  test::TestSystemTrayDelegate* tray_delegate =
-      static_cast<test::TestSystemTrayDelegate*>(
-          Shell::GetInstance()->system_tray_delegate());
+  test::TestSystemTrayDelegate* tray_delegate = GetSystemTrayDelegate();
   tray_delegate->set_should_show_display_notification(true);
   test::DisplayManagerTestApi().SetFirstDisplayAsInternalDisplay();
 
   message_center::MessageCenter* message_center =
       message_center::MessageCenter::Get();
 
   EXPECT_EQ(0u, message_center->NotificationCount());
   EXPECT_FALSE(message_center->HasPopupNotifications());
 
   // Make sure notifications are still displayed when
@@ skipping 219 matching lines @@
                               .GetActiveRotation());
 
   Shell::GetInstance()->screen_orientation_controller()->SetDisplayRotation(
       kNewRotation, display::Display::ROTATION_SOURCE_ACTIVE);
 
   EXPECT_EQ(kNewRotation, display_manager->GetDisplayInfo(kInternalDisplayId)
                               .GetActiveRotation());
 }
 
 }  // namespace ash