Move device/core files to device/base directory.

device/core/device_client.h

-// 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.
-
-#ifndef DEVICE_CORE_DEVICE_CLIENT_H_
-#define DEVICE_CORE_DEVICE_CLIENT_H_
-
-#include "base/macros.h"
-#include "device/core/device_core_export.h"
-
-namespace device {
-
-class HidService;
-class UsbService;
-
-// Interface used by consumers of //device APIs to get pointers to the service
-// singletons appropriate for a given embedding application. For an example see
-// //chrome/browser/chrome_device_client.h.
-class DEVICE_CORE_EXPORT DeviceClient {
- public:
-  // Construction sets the single instance.
-  DeviceClient();
-
-  // Destruction clears the single instance.
-  virtual ~DeviceClient();
-
-  // Returns the single instance of |this|.
-  static DeviceClient* Get();
-
-  // Returns the UsbService instance for this embedder.
-  virtual UsbService* GetUsbService();
-
-  // Returns the HidService instance for this embedder.
-  virtual HidService* GetHidService();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(DeviceClient);
-};
-
-}  // namespace device
-
-#endif  // DEVICE_CORE_DEVICE_CLIENT_H_