Added read-only file error test.

base/test/test_file_util.h

 // Copyright (c) 2010 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_TEST_TEST_FILE_UTIL_H_
 #define BASE_TEST_TEST_FILE_UTIL_H_
 #pragma once
 
 // File utility functions used only by tests.
 
@@ skipping 38 matching lines @@
 // string16 elsewhere for Unicode strings, but in tests it is frequently
 // convenient to be able to compare paths to literals like L"foobar".
 std::wstring FilePathAsWString(const FilePath& path);
 FilePath WStringAsFilePath(const std::wstring& path);
 
 // For testing, make the file unreadable or unwritable.
 // In POSIX, this does not apply to the root user.
 bool MakeFileUnreadable(const FilePath& path) WARN_UNUSED_RESULT;
 bool MakeFileUnwritable(const FilePath& path) WARN_UNUSED_RESULT;
 
+// Gets a blob indicating the permission information for |path|.
+// |length| is the length of the blob.  Zero on failure.
+// Returns the blob pointer, or NULL on failure.
+void* GetPermissionInfo(const FilePath& path, size_t* length);
+
+// Restores the permission information for |path|, given the blob retrieved
+// using |GetPermissionInfo()|.
+// |info| is the pointer to the blob.
+// |length| is the length of the blob.
+// Either |info| or |length| may be NULL/0, in which case nothing happens.
+bool RestorePermissionInfo(const FilePath& path, void* info, size_t length);
+
 }  // namespace file_util
 
 #endif  // BASE_TEST_TEST_FILE_UTIL_H_