chromeos: Remove unused NFC D-Bus client library

device/nfc/nfc_tag_chromeos.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_NFC_NFC_TAG_CHROMEOS_H_
-#define DEVICE_NFC_NFC_TAG_CHROMEOS_H_
-
-#include <memory>
-#include <string>
-
-#include "base/macros.h"
-#include "base/observer_list.h"
-#include "chromeos/dbus/nfc_tag_client.h"
-#include "dbus/object_path.h"
-#include "device/nfc/nfc_tag.h"
-
-namespace chromeos {
-
-class NfcNdefTagTechnologyChromeOS;
-
-// The NfcTagChromeOS class implements device::NfcTag for the Chrome OS
-// platform.
-class NfcTagChromeOS : public device::NfcTag,
-                       public NfcTagClient::Observer {
- public:
-  // device::NfcTag overrides.
-  void AddObserver(device::NfcTag::Observer* observer) override;
-  void RemoveObserver(device::NfcTag::Observer* observer) override;
-  std::string GetIdentifier() const override;
-  TagType GetType() const override;
-  bool IsReadOnly() const override;
-  device::NfcTag::Protocol GetSupportedProtocol() const override;
-  device::NfcTagTechnology::TechnologyTypeMask GetSupportedTechnologies()
-      const override;
-  bool IsReady() const override;
-  device::NfcNdefTagTechnology* GetNdefTagTechnology() override;
-
-  // NfcTagClient::Observer overrides.
-  void TagPropertyChanged(const dbus::ObjectPath& object_path,
-                          const std::string& property_name) override;
-  void TagPropertiesReceived(const dbus::ObjectPath& object_path) override;
-
-  // Object path representing the remote tag object.
-  const dbus::ObjectPath& object_path() const { return object_path_; }
-
- private:
-  friend class NfcAdapterChromeOS;
-
-  explicit NfcTagChromeOS(const dbus::ObjectPath& object_path);
-  ~NfcTagChromeOS() override;
-
-  // Object path of the tag that we are currently tracking.
-  dbus::ObjectPath object_path_;
-
-  // Stores whether or not the initial set of properties have been received.
-  bool is_ready_;
-
-  // The NfcNdefTagTechnology instance that allows users to perform NDEF
-  // read and write on this tag.
-  std::unique_ptr<NfcNdefTagTechnologyChromeOS> ndef_technology_;
-
-  // List of observers interested in event notifications from us.
-  base::ObserverList<device::NfcTag::Observer> observers_;
-
-  DISALLOW_COPY_AND_ASSIGN(NfcTagChromeOS);
-};
-
-}  // namespace chromeos
-
-#endif  // DEVICE_NFC_NFC_TAG_CHROMEOS_H_