Add support for GetHomeDir for Mac and Windows.

base/base_paths_posix.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_BASE_PATHS_POSIX_H_
 #define BASE_BASE_PATHS_POSIX_H_
 
 // This file declares windows-specific path keys for the base module.
 // These can be used with the PathService to access various special
 // directories and files.
 
 namespace base {
 
 enum {
   PATH_POSIX_START = 400,
 
   DIR_CACHE,    // Directory where to put cache data.  Note this is
                 // *not* where the browser cache lives, but the
                 // browser cache can be a subdirectory.
                 // This is $XDG_CACHE_HOME on Linux and
                 // ~/Library/Caches on Mac.
-  DIR_HOME,     // $HOME on POSIX-like systems.
-
   PATH_POSIX_END
 };
 
 }  // namespace base
 
 #endif  // BASE_BASE_PATHS_POSIX_H_