chromeos: Cleanup class/struct fwd declarations

chromeos/dbus/mock_permission_broker_client.h

 // Copyright 2015 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 CHROMEOS_DBUS_MOCK_PERMISSION_BROKER_CLIENT_H_
 #define CHROMEOS_DBUS_MOCK_PERMISSION_BROKER_CLIENT_H_
 
 #include <stdint.h>
 
 #include "chromeos/dbus/permission_broker_client.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
-namespace dbus {
-class FileDescriptor;
-}  // namespace dbus
-
 namespace chromeos {
 
 class MockPermissionBrokerClient : public PermissionBrokerClient {
  public:
   MockPermissionBrokerClient();
   ~MockPermissionBrokerClient() override;
 
   MOCK_METHOD1(Init, void(dbus::Bus* bus));
   MOCK_METHOD2(CheckPathAccess,
                void(const std::string& path, const ResultCallback& callback));
@@ skipping 17 matching lines @@
                     const ResultCallback& callback));
   MOCK_METHOD3(ReleaseUdpPort,
                void(uint16_t port,
                     const std::string& interface,
                     const ResultCallback& callback));
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_MOCK_PERMISSION_BROKER_CLIENT_H_