components: Cleanup class/struct fwd declarations

components/drive/file_system_core_util.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 COMPONENTS_DRIVE_FILE_SYSTEM_CORE_UTIL_H_
 #define COMPONENTS_DRIVE_FILE_SYSTEM_CORE_UTIL_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/files/file_path.h"
 #include "components/drive/file_errors.h"
 #include "url/gurl.h"
 
 namespace drive {
 
-class DriveAppRegistry;
-class DriveServiceInterface;
-class FileSystemInterface;
-
 namespace util {
 
 // "drive" diretory's local ID is fixed to this value.
 const char kDriveGrandRootLocalId[] = "<drive>";
 
 // "drive/other" diretory's local ID is fixed to this value.
 const char kDriveOtherDirLocalId[] = "<other>";
 
 // "drive/trash" diretory's local ID is fixed to this value.
 const char kDriveTrashDirLocalId[] = "<trash>";
@@ skipping 50 matching lines @@
 // Reads URL from a GDoc file.
 GURL ReadUrlFromGDocFile(const base::FilePath& file_path);
 
 // Reads resource ID from a GDoc file.
 std::string ReadResourceIdFromGDocFile(const base::FilePath& file_path);
 
 }  // namespace util
 }  // namespace drive
 
 #endif  // COMPONENTS_DRIVE_FILE_SYSTEM_CORE_UTIL_H_