Fixing gcc 4.7 building problems.

chrome/browser/policy/policy_path_parser_linux.cc

 // Copyright (c) 2011 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 <pwd.h>
+#include <sys/types.h>
+#include <unistd.h>
 
 #include "chrome/browser/policy/policy_path_parser.h"
 
 #include "base/logging.h"
 
 namespace policy {
 
 namespace path_parser {
 
 const char* kMachineNamePolicyVarName = "${machine_name}";
@@ skipping 31 matching lines @@
     } else {
       LOG(ERROR) << "Machine name variable can not be resolved.";
     }
   }
   return result;
 }
 
 }  // namespace path_parser
 
 }  // namespace policy