Use multi-profile mount point by default after browser crash and in Guest session.

chrome/browser/chromeos/profiles/profile_helper.h

Index: chrome/browser/chromeos/profiles/profile_helper.h
diff --git a/chrome/browser/chromeos/profiles/profile_helper.h b/chrome/browser/chromeos/profiles/profile_helper.h
index 611690ff90f4d32da3f419b78ee902b7116f35e5..2d11609a53a232ad80921203bd728849810f3433 100644
--- a/chrome/browser/chromeos/profiles/profile_helper.h
+++ b/chrome/browser/chromeos/profiles/profile_helper.h
@@ -63,6 +63,9 @@ class ProfileHelper : public BrowsingDataRemover::Observer,
   // Returns active user profile dir in a format [u-$hash].
   base::FilePath GetActiveUserProfileDir();
 
+  // Returns user profile dir in a format [u-user_id_hash].
+  base::FilePath GetUserProfileDir(const std::string& user_id_hash);

[Dmitry Polukhin, 2013/09/18 15:46:06]

I made similar function UserManager::GetUserProfileDir, I think we need to use
it and remove Chrome OS specific code from Profiles.

[Nikita (slow), 2013/09/18 16:22:55]

I don't see this function in user_manager.h / user_manager_impl.h
 
You mean ProfileManager? Yes, it needs to be cleaned up but looking at
profile_manager.cc I see that UserManager is used only once:

if (chromeos::UserManager::Get()->IsLoggedInAsGuest())

While ProfileHelper was decided to be a way to capture Chrome OS specific code
paths that need to be executed in ProfileManager. So I would prefer to keep to
that approach.

[Dmitry Polukhin, 2013/09/18 16:48:43]

As we discussed offline UserManagerImpl::GetUserProfileDir needs to be updated
too.

[Nikita (slow), 2013/09/18 18:04:37]

Done.

+
   // Should called once after UserManager instance has been created.
   void Initialize();