Add the methods to change and get a posix file permission to file_util.

base/file_util.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.
 
 // This file contains utility functions for dealing with the local
 // filesystem.
 
 #ifndef BASE_FILE_UTIL_H_
 #define BASE_FILE_UTIL_H_
 #pragma once
@@ skipping 83 matching lines @@
 BASE_EXPORT int64 ComputeFilesSize(const FilePath& directory,
                                    const FilePath::StringType& pattern);
 
 // Deletes the given path, whether it's a file or a directory.
 // If it's a directory, it's perfectly happy to delete all of the
 // directory's contents.  Passing true to recursive deletes
 // subdirectories and their contents as well.
 // Returns true if successful, false otherwise.
 //
 // In posix environment and if |path| is a symbolic link, this deletes only
-// the symlink. (even if the symlink deferences to a non-existent file)
+// the symlink. (even if the symlink points to a non-existent file)
 //
 // WARNING: USING THIS WITH recursive==true IS EQUIVALENT
 //          TO "rm -rf", SO USE WITH CAUTION.
 BASE_EXPORT bool Delete(const FilePath& path, bool recursive);
 
 #if defined(OS_WIN)
 // Schedules to delete the given path, whether it's a file or a directory, until
 // the operating system is restarted.
 // Note:
 // 1) The file/directory to be deleted should exist in a temp folder.
@@ skipping 74 matching lines @@
 BASE_EXPORT bool ReadFromFD(int fd, char* buffer, size_t bytes);
 
 // Creates a symbolic link at |symlink| pointing to |target|.  Returns
 // false on failure.
 BASE_EXPORT bool CreateSymbolicLink(const FilePath& target,
                                     const FilePath& symlink);
 
 // Reads the given |symlink| and returns where it points to in |target|.
 // Returns false upon failure.
 BASE_EXPORT bool ReadSymbolicLink(const FilePath& symlink, FilePath* target);
+
+// Bits ans masks of the file permission.
+enum FilePermissionBits {
+  FILE_PERMISSION_MASK              = S_IRWXU | S_IRWXG | S_IRWXO,
+  FILE_PERMISSION_USER_MASK         = S_IRWXU,
+  FILE_PERMISSION_GROUP_MASK        = S_IRWXG,
+  FILE_PERMISSION_OTHERS_MASK       = S_IRWXO,
+
+  FILE_PERMISSION_READ_BY_USER      = S_IRUSR,
+  FILE_PERMISSION_WRITE_BY_USER     = S_IWUSR,
+  FILE_PERMISSION_EXECUTE_BY_USER   = S_IXUSR,
+  FILE_PERMISSION_READ_BY_GROUP     = S_IRGRP,
+  FILE_PERMISSION_WRITE_BY_GROUP    = S_IWGRP,
+  FILE_PERMISSION_EXECUTE_BY_GROUP  = S_IXGRP,
+  FILE_PERMISSION_READ_BY_OTHERS    = S_IROTH,
+  FILE_PERMISSION_WRITE_BY_OTHERS   = S_IWOTH,
+  FILE_PERMISSION_EXECUTE_BY_OTHERS = S_IXOTH,
+};
+
+// Reads the permission of the given |path|, storing the file permission
+// bits in |mode|. If |path| is symbolic link, |mode| is the permission of
+// a file which the symlink points to.
+BASE_EXPORT bool GetPosixFilePermissions(const FilePath& path,
+                                         int* mode);
+// Sets the permission of the given |path|. If |path| is symbolic link, sets
+// the permission of a file which the symlink points to.
+BASE_EXPORT bool SetPosixFilePermissions(const FilePath& path,
+                                         int mode);
 #endif  // defined(OS_POSIX)
 
 #if defined(OS_WIN)
 enum ShortcutOptions {
   SHORTCUT_NO_OPTIONS = 0,
   // Set DualMode property for Windows 8 Metro-enabled shortcuts.
   SHORTCUT_DUAL_MODE = 1 << 0,
   // Create a new shortcut (overwriting if necessary).
   SHORTCUT_CREATE_ALWAYS = 1 << 1,
 };
@@ skipping 429 matching lines @@
 };
 
 // Attempts determine the FileSystemType for |path|.
 // Returns false if |path| doesn't exist.
 BASE_EXPORT bool GetFileSystemType(const FilePath& path, FileSystemType* type);
 #endif
 
 }  // namespace file_util
 
 #endif  // BASE_FILE_UTIL_H_