cros: Use SessionController for lock starting code

chrome/browser/ui/ash/session_controller_client.h

 // Copyright 2016 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.
 
 #ifndef CHROME_BROWSER_UI_ASH_SESSION_CONTROLLER_CLIENT_H_
 #define CHROME_BROWSER_UI_ASH_SESSION_CONTROLLER_CLIENT_H_
 
 #include "ash/public/interfaces/session_controller.mojom.h"
 #include "base/callback_forward.h"
 #include "base/macros.h"
@@ skipping 19 matching lines @@
       public user_manager::UserManager::UserSessionStateObserver,
       public user_manager::UserManager::Observer,
       public session_manager::SessionManagerObserver,
       public content::NotificationObserver {
  public:
   SessionControllerClient();
   ~SessionControllerClient() override;
 
   static SessionControllerClient* Get();
 
+  // Calls SessionController to start locking ash. |callback| will be invoked
+  // to indicate whether the lock is successful. If |locked| is true, the post
+  // lock animation is finished and ash is fully locked. Otherwise, the lock
+  // is failed somehow.
+  using StartLockCallback = base::Callback<void(bool locked)>;
+  void StartLock(StartLockCallback callback);
+
   // Calls ash SessionController to run unlock animation.
   // |animation_finished_callback| will be invoked when the animation finishes.
   void RunUnlockAnimation(base::Closure animation_finished_callback);
 
   // ash::mojom::SessionControllerClient:
   void RequestLockScreen() override;
   void SwitchActiveUser(const AccountId& account_id) override;
   void CycleActiveUser(ash::CycleUserDirection direction) override;
 
   // user_manager::UserManager::UserSessionStateObserver:
@@ skipping 48 matching lines @@
 
   // For observing NOTIFICATION_APP_TERMINATING.
   content::NotificationRegistrar registrar_;
 
   ash::mojom::SessionInfoPtr last_sent_session_info_;
 
   DISALLOW_COPY_AND_ASSIGN(SessionControllerClient);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_SESSION_CONTROLLER_CLIENT_H_