Use OnceCallback on Mojo interfaces in //device/gamepad

device/gamepad/gamepad_monitor.h

 // Copyright (c) 2012 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 DEVICE_GAMEPAD_GAMEPAD_MONITOR_H_
 #define DEVICE_GAMEPAD_GAMEPAD_MONITOR_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "device/gamepad/gamepad_consumer.h"
@@ skipping 14 matching lines @@
   ~GamepadMonitor() override;
 
   static void Create(const service_manager::BindSourceInfo& source_info,
                      mojom::GamepadMonitorRequest request);
 
   // GamepadConsumer implementation.
   void OnGamepadConnected(unsigned index, const Gamepad& gamepad) override;
   void OnGamepadDisconnected(unsigned index, const Gamepad& gamepad) override;
 
   // mojom::GamepadMonitor implementation.
-  void GamepadStartPolling(
-      const GamepadStartPollingCallback& callback) override;
-  void GamepadStopPolling(const GamepadStopPollingCallback& callback) override;
+  void GamepadStartPolling(GamepadStartPollingCallback callback) override;
+  void GamepadStopPolling(GamepadStopPollingCallback callback) override;
   void SetObserver(mojom::GamepadObserverPtr gamepad_observer) override;
 
  private:
   mojom::GamepadObserverPtr gamepad_observer_;
   bool is_started_;
 
   DISALLOW_COPY_AND_ASSIGN(GamepadMonitor);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_GAMEPAD_GAMEPAD_MONITOR_H_