Remove FileUtilProxy:DeleteFile().

base/files/file_util_proxy.h

 // Copyright (c) 2012 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 BASE_FILES_FILE_UTIL_PROXY_H_
 #define BASE_FILES_FILE_UTIL_PROXY_H_
 
 #include "base/base_export.h"
 #include "base/callback_forward.h"
 #include "base/files/file.h"
@@ skipping 17 matching lines @@
                         const File::Info&)> GetFileInfoCallback;
 
   // Retrieves the information about a file. It is invalid to pass a null
   // callback.
   // This returns false if task posting to |task_runner| has failed.
   static bool GetFileInfo(
       TaskRunner* task_runner,
       const FilePath& file_path,
       const GetFileInfoCallback& callback);
 
-  // Deletes a file or a directory.
-  // It is an error to delete a non-empty directory with recursive=false.
-  // This returns false if task posting to |task_runner| has failed.
-  static bool DeleteFile(TaskRunner* task_runner,
-                         const FilePath& file_path,
-                         bool recursive,
-                         const StatusCallback& callback);
-
   // Touches a file. The callback can be null.
   // This returns false if task posting to |task_runner| has failed.
   static bool Touch(
       TaskRunner* task_runner,
       const FilePath& file_path,
       const Time& last_access_time,
       const Time& last_modified_time,
       const StatusCallback& callback);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(FileUtilProxy);
 };
 
 }  // namespace base
 
 #endif  // BASE_FILES_FILE_UTIL_PROXY_H_