[cryptohome] make guest-mode homedir mount with -rwx------

mount.cc

Index: mount.cc
diff --git a/mount.cc b/mount.cc
index ff2106fa401a6883be22740b319682e0ec9b2cca..0121a82ef317d77082754ebd2b5a4dcae599d2ec 100644
--- a/mount.cc
+++ b/mount.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009-2010 The Chromium OS Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -849,6 +849,8 @@ bool Mount::MountGuestCryptohome() const {
       return false;
     }
   }
+  if (!platform_->SetPermissions(home_dir_, S_IRUSR | S_IWUSR | S_IXUSR))

[Will Drewry, 2011/04/21 21:42:09]

Doesn't this need to call platform_->Unmount if it fails?

(nit: it'd be nice to have it as a constant like kDefaultMask, but since it is
only used here, I think it's fine as is.)

+    return false;
   CopySkeleton();
   return true;
 }