chromeos: Avoid bogus child account warning at startup.

chrome/browser/supervised_user/child_accounts/child_account_service.cc

 // Copyright 2014 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/supervised_user/child_accounts/child_account_service.h"
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/feature_list.h"
 #include "base/memory/ptr_util.h"
@@ skipping 280 matching lines @@
   family_fetch_timer_.Start(
       FROM_HERE, delay, this, &ChildAccountService::StartFetchingFamilyInfo);
 }
 
 void ChildAccountService::PropagateChildStatusToUser(bool is_child) {
 #if defined(OS_CHROMEOS)
   user_manager::User* user =
       chromeos::ProfileHelper::Get()->GetUserByProfile(profile_);
   if (user) {
     user_manager::UserManager::Get()->ChangeUserChildStatus(user, is_child);
-  } else {
-    LOG(WARNING) <<
-        "User instance wasn't found while setting child account flag.";
+  } else if (!chromeos::ProfileHelper::Get()->IsSigninProfile(profile_)) {
+    LOG(WARNING)

[Bernhard Bauer, 2016/08/10 14:23:57]

Actually, would it make sense to have a DCHECK/CHECK here? Could this
legitimately happen outside of the signin profile?

[Daniel Erat, 2016/08/10 15:08:40]

sorry, i have no idea -- i've never looked at this code before yesterday.

re switching it to a check, is it a situation that means that we should expect
undefined behavior or security issues? is it likely that restarting chrome will
clear it up? if not, i don't think a check is appropriate.

[Bernhard Bauer, 2016/08/10 17:17:29]

Hm, I'm thinking this is a situation that is _supposed_ to never happen (at
least I don't know when it would legitimately happen), so a DCHECK would be
appropriate (cf.
https://chromium.googlesource.com/chromium/src/+/master/styleguide/c++/c++.md...).

[Daniel Erat, 2016/08/10 20:12:12]

how about LOG(DFATAL)? then we get a crash in debug builds as if we used
DCHECK() and an error message in release builds.

+        << "User instance wasn't found while setting child account flag.";
   }
 #endif
 }
 
 void ChildAccountService::SetFirstCustodianPrefs(
     const FamilyInfoFetcher::FamilyMember& custodian) {
   profile_->GetPrefs()->SetString(prefs::kSupervisedUserCustodianName,
                                   custodian.display_name);
   profile_->GetPrefs()->SetString(prefs::kSupervisedUserCustodianEmail,
                                   custodian.email);
@@ skipping 27 matching lines @@
 }
 
 void ChildAccountService::ClearSecondCustodianPrefs() {
   profile_->GetPrefs()->ClearPref(prefs::kSupervisedUserSecondCustodianName);
   profile_->GetPrefs()->ClearPref(prefs::kSupervisedUserSecondCustodianEmail);
   profile_->GetPrefs()->ClearPref(
       prefs::kSupervisedUserSecondCustodianProfileURL);
   profile_->GetPrefs()->ClearPref(
       prefs::kSupervisedUserSecondCustodianProfileImageURL);
 }