Determine whether user is ephemeral when coming back from a crash

chrome/browser/chromeos/login/user_manager_impl.cc

 // 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.
 
 #include "chrome/browser/chromeos/login/user_manager_impl.h"
 
 #include <vector>
 
 #include "ash/shell.h"
 #include "ash/desktop_background/desktop_background_controller.h"
@@ skipping 870 matching lines @@
 
 bool UserManagerImpl::IsEphemeralUser(const std::string& email) const {
   // The guest user always is ephemeral.
   if (email == kGuestUser)
     return true;
 
   // The currently logged-in user is ephemeral iff logged in as ephemeral.
   if (logged_in_user_ && (email == logged_in_user_->email()))
     return is_current_user_ephemeral_;
 
+  // If the browser is coming back after a crash in the middle of a session, the
+  // user's cryptohome will already be mounted. When this is the case, the user
+  // is ephemeral iff the cryptohome was mounted as ephemeral.
+  bool is_mounted;
+  bool is_ephemeral_mount;
+  if (DBusThreadManager::Get()->GetCryptohomeClient()->

[Nikita (slow), 2012/05/10 09:10:12]

That doesn't seem like a correct solution i.e. always call a blocking call here.

You should call that method async early on and then use cached value.

[Nikita (slow), 2012/05/10 09:19:56]

When Chrome is restarted after crash, UserManager::UserLoggedIn() is called,
which calls IsEphemeralUser(). First ever call should initialize
is_current_user_ephemeral_ in async way so subsequent calls use that cached
value.

We do distinguish case when UserLoggedIn is called after crash so you should
pass some bool variable to UserLoggedIn in that case so that async Cryptohome
call is done. That async call should not happen during normal sign in otherwise
it would delay that.

Here's the code path for reload after crash:
http://code.google.com/codesearch#OAMlx_jo-ck/src/chrome/browser/chromeos/chr...

[bartfab (slow), 2012/05/10 09:21:44]

Thanks. I was looking through the code just now to find out how to better handle
the restart-after-crash case. I will dive right into it now that I know where to
look.

+          IsMountedForUser(email, &is_mounted, &is_ephemeral_mount)) {
+    if (is_mounted)
+      return is_ephemeral_mount;
+  }
+
   // Any other user is ephemeral iff ephemeral users are enabled, the user is
   // not the owner and is not in the persistent list.
   return AreEphemeralUsersEnabled() &&
       (email != owner_email_) &&
       !FindUserInList(email);
 }
 
 const User* UserManagerImpl::FindUserInList(const std::string& email) const {
   const UserList& users = GetUsers();
   for (UserList::const_iterator it = users.begin(); it != users.end(); ++it) {
@@ skipping 407 matching lines @@
     BrowserThread::PostTask(
         BrowserThread::FILE,
         FROM_HERE,
         base::Bind(&UserManagerImpl::DeleteUserImage,
                    base::Unretained(this),
                    image_path));
   }
 }
 
 }  // namespace chromeos