Use OnceCallback on Mojo interfaces in //ash

ash/session/session_controller.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 ASH_SESSION_SESSION_CONTROLLER_H_
 #define ASH_SESSION_SESSION_CONTROLLER_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 102 matching lines @@
   // NOTE: Prefer GetSessionState() in new code because the concept of
   // SessionState more closes matches the state in chrome.
   LoginStatus login_status() const { return login_status_; }
 
   // mojom::SessionController
   void SetClient(mojom::SessionControllerClientPtr client) override;
   void SetSessionInfo(mojom::SessionInfoPtr info) override;
   void UpdateUserSession(mojom::UserSessionPtr user_session) override;
   void SetUserSessionOrder(
       const std::vector<uint32_t>& user_session_order) override;
-  void StartLock(const StartLockCallback& callback) override;
+  void StartLock(StartLockCallback callback) override;
   void NotifyChromeLockAnimationsComplete() override;
-  void RunUnlockAnimation(const RunUnlockAnimationCallback& callback) override;
+  void RunUnlockAnimation(RunUnlockAnimationCallback callback) override;
   void NotifyChromeTerminating() override;
 
   // Test helpers.
   void ClearUserSessionsForTest();
   void FlushMojoForTest();
   void LockScreenAndFlushForTest();
 
  private:
   void SetSessionState(session_manager::SessionState state);
   void AddUserSession(mojom::UserSessionPtr user_session);
@@ skipping 47 matching lines @@
   base::ObserverList<ash::SessionObserver> observers_;
 
   base::WeakPtrFactory<SessionController> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SessionController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SESSION_SESSION_CONTROLLER_H_