Update the AvatarMenu when a supervised user's custodian info changes.

chrome/browser/profiles/avatar_menu.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/profiles/avatar_menu.h"
 
 #include "ash/ash_switches.h"
 #include "base/bind.h"
 #include "base/i18n/case_conversion.h"
 #include "base/metrics/field_trial.h"
@@ skipping 46 matching lines @@
       observer_(observer),
       browser_(browser) {
   DCHECK(profile_info_);
   // Don't DCHECK(browser_) so that unit tests can reuse this ctor.
 
   ActiveBrowserChanged(browser_);
 
   // Register this as an observer of the info cache.
   registrar_.Add(this, chrome::NOTIFICATION_PROFILE_CACHED_INFO_CHANGED,
       content::NotificationService::AllSources());
+
+#if defined(ENABLE_MANAGED_USERS)
+  // Register this as an observer of the SupervisedUserService to be notified
+  // of changes to the custodian info.
+  if (browser_) {
+    SupervisedUserService* service =
+        SupervisedUserServiceFactory::GetForProfile(browser_->profile());

[noms (inactive), 2014/09/25 14:22:22]

Is it possible to be in a state where browser_->profile() is the Guest Profile,
for which service might be NULL? 

[Marc Treib, 2014/09/25 14:50:56]

browser_->profile() can be the guest profile, but service still isn't NULL.
Maybe it can be NULL in tests? I haven't checked that yet.

[Bernhard Bauer, 2014/09/25 15:15:48]

Yeah, I don't think we set it to NULL for testing profiles.

+    service->AddObserver(this);
+  }
+#endif
 }
 
 AvatarMenu::~AvatarMenu() {
+#if defined(ENABLE_MANAGED_USERS)
+  if (browser_) {
+    SupervisedUserService* service =
+        SupervisedUserServiceFactory::GetForProfile(browser_->profile());
+    service->RemoveObserver(this);

[Bernhard Bauer, 2014/09/25 15:15:48]

A ScopedObserver might be useful here, to do this automatically at destruction.

[Marc Treib, 2014/09/25 15:30:28]

Done.

+  }
+#endif
 }
 
 AvatarMenu::Item::Item(size_t menu_index,
                        size_t profile_index,
                        const gfx::Image& icon)
     : icon(icon),
       active(false),
       signed_in(false),
       signin_required(false),
       menu_index(menu_index),
@@ skipping 147 matching lines @@
 }
 
 void AvatarMenu::Observe(int type,
                          const content::NotificationSource& source,
                          const content::NotificationDetails& details) {
   DCHECK_EQ(chrome::NOTIFICATION_PROFILE_CACHED_INFO_CHANGED, type);
   RebuildMenu();
   if (observer_)
     observer_->OnAvatarMenuChanged(this);
 }
+
+#if defined(ENABLE_MANAGED_USERS)
+void AvatarMenu::OnCustodianInfoChanged() {
+  RebuildMenu();
+  if (observer_)
+    observer_->OnAvatarMenuChanged(this);
+}
+#endif