Use mojo SystemTray interfaces for both mash and classic ash

ash/mus/window_manager_application.cc

 // Copyright 2015 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/mus/window_manager_application.h"
 
 #include <utility>
 
 #include "ash/common/material_design/material_design_controller.h"
+#include "ash/common/system/tray/system_tray_controller.h"
 #include "ash/common/wm_shell.h"
 #include "ash/mus/accelerators/accelerator_registrar_impl.h"
 #include "ash/mus/native_widget_factory_mus.h"
 #include "ash/mus/shelf_delegate_mus.h"
-#include "ash/mus/system_tray_delegate_mus.h"
 #include "ash/mus/wallpaper_delegate_mus.h"
 #include "ash/mus/window_manager.h"
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "services/shell/public/cpp/connection.h"
 #include "services/shell/public/cpp/connector.h"
 #include "services/tracing/public/cpp/provider.h"
 #include "services/ui/common/event_matcher_util.h"
 #include "services/ui/public/cpp/gpu_service.h"
 #include "services/ui/public/cpp/window.h"
@@ skipping 144 matching lines @@
 void WindowManagerApplication::Create(const shell::Identity& remote_identity,
                                       mojom::ShelfControllerRequest request) {
   mojom::ShelfController* shelf_controller =
       static_cast<ShelfDelegateMus*>(WmShell::Get()->shelf_delegate());
   DCHECK(shelf_controller);
   shelf_controller_bindings_.AddBinding(shelf_controller, std::move(request));
 }
 
 void WindowManagerApplication::Create(const shell::Identity& remote_identity,
                                       mojom::SystemTrayRequest request) {
-  mojom::SystemTray* system_tray = SystemTrayDelegateMus::Get();
+  // Look mom, no cast!
+  mojom::SystemTray* system_tray = WmShell::Get()->system_tray_controller();
   DCHECK(system_tray);
   system_tray_bindings_.AddBinding(system_tray, std::move(request));
 }
 
 void WindowManagerApplication::Create(
     const ::shell::Identity& remote_identity,
     mojom::WallpaperControllerRequest request) {
   mojom::WallpaperController* wallpaper_controller =
       static_cast<WallpaperDelegateMus*>(WmShell::Get()->wallpaper_delegate());
   DCHECK(wallpaper_controller);
@@ skipping 19 matching lines @@
       base::Bind(&WindowManagerApplication::OnAcceleratorRegistrarDestroyed,
                  base::Unretained(this))));
 }
 
 void WindowManagerApplication::ScreenlockStateChanged(bool locked) {
   window_manager_->SetScreenLocked(locked);
 }
 
 }  // namespace mus
 }  // namespace ash