[net] Cleanup filename_util and make it portable.

net/base/filename_util.cc

 // Copyright 2014 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.
 
 #include "net/base/filename_util.h"
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "base/strings/string_util.h"
@@ skipping 120 matching lines @@
     ReplaceSubstringsAfterOffset(&new_path, 0, "//", "/");
     path.swap(new_path);
   } while (new_path != path);
 
   file_path_str.assign(path);
 #endif  // !defined(OS_WIN)
 
   return !file_path_str.empty();
 }
 
-void GenerateSafeFileName(const std::string& mime_type,
-                          bool ignore_extension,
-                          base::FilePath* file_path) {
-  // Make sure we get the right file extension
-  EnsureSafeExtension(mime_type, ignore_extension, file_path);
-
-#if defined(OS_WIN)
-  // Prepend "_" to the file name if it's a reserved name
-  base::FilePath::StringType leaf_name = file_path->BaseName().value();
-  DCHECK(!leaf_name.empty());
-  if (IsReservedName(leaf_name)) {
-    leaf_name = base::FilePath::StringType(FILE_PATH_LITERAL("_")) + leaf_name;
-    *file_path = file_path->DirName();
-    if (file_path->value() == base::FilePath::kCurrentDirectory) {
-      *file_path = base::FilePath(leaf_name);
-    } else {
-      *file_path = file_path->Append(leaf_name);
-    }
-  }
-#endif
-}
-
 }  // namespace net