device: Cleanup class/struct forward declarations

device/bluetooth/bluez/bluetooth_gatt_descriptor_bluez.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_BLUEZ_BLUETOOTH_GATT_DESCRIPTOR_BLUEZ_H_
 #define DEVICE_BLUETOOTH_BLUEZ_BLUETOOTH_GATT_DESCRIPTOR_BLUEZ_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "dbus/object_path.h"
 #include "device/bluetooth/bluetooth_gatt_descriptor.h"
 
 namespace bluez {
 
-class BluetoothGattCharacteristicBlueZ;
-
 // The BluetoothGattDescriptorBlueZ class implements BluetoothGattDescriptor for
 // GATT characteristic descriptors for platforms that use BlueZ.
 class BluetoothGattDescriptorBlueZ
     : public virtual device::BluetoothGattDescriptor {
  public:
   // device::BluetoothGattDescriptor overrides.
   std::string GetIdentifier() const override;
 
   // Object path of the underlying D-Bus characteristic.
   const dbus::ObjectPath& object_path() const { return object_path_; }
@@ skipping 11 matching lines @@
 
   // Object path of the D-Bus descriptor object.
   dbus::ObjectPath object_path_;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothGattDescriptorBlueZ);
 };
 
 }  // namespace bluez
 
 #endif  // DEVICE_BLUETOOTH_BLUEZ_BLUETOOTH_GATT_DESCRIPTOR_BLUEZ_H_