Implement DBus changes needed for notifications.

device/bluetooth/dbus/bluetooth_gatt_descriptor_delegate_wrapper.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 DEVICE_BLUETOOTH_DBUS_BLUETOOTH_GATT_DESCRIPTOR_DELEGATE_WRAPPER_H_
 #define DEVICE_BLUETOOTH_DBUS_BLUETOOTH_GATT_DESCRIPTOR_DELEGATE_WRAPPER_H_
 
 #include <cstdint>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "device/bluetooth/bluetooth_local_gatt_service.h"
 #include "device/bluetooth/bluez/bluetooth_gatt_service_bluez.h"
 #include "device/bluetooth/bluez/bluetooth_local_gatt_service_bluez.h"
 #include "device/bluetooth/dbus/bluetooth_gatt_attribute_value_delegate.h"
 
 namespace bluez {
 
 class BluetoothLocalGattDescriptorBlueZ;
 
 // Wrapper class around AttributeValueDelegate to handle descriptors.
 class BluetoothGattDescriptorDelegateWrapper
     : public BluetoothGattAttributeValueDelegate {
  public:
   BluetoothGattDescriptorDelegateWrapper(
       BluetoothLocalGattServiceBlueZ* service,
       BluetoothLocalGattDescriptorBlueZ* descriptor);
 
+  // BluetoothGattAttributeValueDelegate overrides:
   void GetValue(
       const device::BluetoothLocalGattService::Delegate::ValueCallback&
           callback,
       const device::BluetoothLocalGattService::Delegate::ErrorCallback&
           error_callback) override;
   void SetValue(
       const std::vector<uint8_t>& value,
       const base::Closure& callback,
       const device::BluetoothLocalGattService::Delegate::ErrorCallback&
           error_callback) override;
+  void StartNotifications() override {}
+  void StopNotifications() override {}
 
  private:
   BluetoothLocalGattServiceBlueZ* service_;
   BluetoothLocalGattDescriptorBlueZ* descriptor_;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothGattDescriptorDelegateWrapper);
 };
 
 }  // namespace bluez
 
 #endif  // DEVICE_BLUETOOTH_DBUS_BLUETOOTH_GATT_DESCRIPTOR_DELEGATE_WRAPPER_H_