[Sync] Fix sync backup for supervised users

chrome/browser/sync/profile_sync_service.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/sync/profile_sync_service.h"
 
 #include <cstddef>
 #include <map>
 #include <vector>
 
@@ skipping 310 matching lines @@
   DCHECK(sync_error_controller_ == NULL)
       << "Initialize() called more than once.";
   sync_error_controller_.reset(new SyncErrorController(this));
   AddObserver(sync_error_controller_.get());
 #endif
 
   bool running_rollback = false;
   if (browser_sync::BackupRollbackController::IsBackupEnabled()) {
     // Backup is needed if user's not signed in or signed in but previous
     // backup didn't finish, i.e. backend didn't switch from backup to sync.
-    need_backup_ = signin_->GetEffectiveUsername().empty() ||
-        sync_prefs_.GetFirstSyncTime().is_null();
+    // Note that backup is never performed for supervised users (which always
+    // start with a fresh profile anyways).
+    need_backup_ = (signin_->GetEffectiveUsername().empty() ||

[Marc Treib, 2014/09/25 09:31:51]

If you want to exclude supervised users, I think it would be easier to not use
the SigninManagerWrapper here, and instead just ask the SigninManager directly
for the username, i.e.
signin_->GetOriginal()->GetAuthenticatedUsername().empty()
That way you don't need the extra IsSupervised check.

[Nicolas Zea, 2014/09/26 01:26:48]

Unfortunately I don't think that will work. The first sync time is still null. I
need to distinguish that its a supervised user and have that override the other
logic.

That said, the alternative is to fix the logic in supervised user service and
make backup work properly. The new patchset does that (although the integration
tests need more work to have proper coverage. Filed 417930 for that).

+        sync_prefs_.GetFirstSyncTime().is_null()) &&
+        !profile_->IsSupervised();
 
     // Try to resume rollback if it didn't finish in last session.
     running_rollback = backup_rollback_controller_.StartRollback();
   } else {
     need_backup_ = false;
   }
 
 #if defined(ENABLE_PRE_SYNC_BACKUP)
   if (!running_rollback && signin_->GetEffectiveUsername().empty()) {
     CleanUpBackup();
@@ skipping 2377 matching lines @@
                  true));
 }
 
 bool ProfileSyncService::NeedBackup() const {
   return need_backup_;
 }
 
 base::Time ProfileSyncService::GetDeviceBackupTimeForTesting() const {
   return device_info_sync_service_->GetLocalDeviceBackupTime();
 }