Add BackupRollbackController for starting backup/rollback

chrome/browser/sync/backup_rollback_controller.h

+// Copyright (c) 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.
+
+#ifndef CHROME_BROWSER_SYNC_BACKUP_ROLLBACK_CONTROLLER_H_
+#define CHROME_BROWSER_SYNC_BACKUP_ROLLBACK_CONTROLLER_H_
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+
+class ManagedUserSigninManagerWrapper;
+
+namespace sync_driver {
+class SyncPrefs;
+}
+
+namespace browser_sync {
+
+// BackupRollbackController takes two closures for starting backup/rollback
+// process. It calls the closures according to user's signin status or
+// received rollback command.
+class BackupRollbackController {
+ public:
+  BackupRollbackController(sync_driver::SyncPrefs* sync_prefs,
+                           const ManagedUserSigninManagerWrapper* signin,

[Nicolas Zea, 2014/05/06 18:54:09]

I'm not sure this is the class you want to use. Do you specifically care about
managed users here? Wouldn't SigningManagerBase be more appropriate?

[haitaol1, 2014/05/07 21:34:17]

By using ManagedUserSigninManagerWrapper, backup/rollback is never started for
managed user because planpen uses a pseudo account always. This is probably the
safe thing to do.

On 2014/05/06 18:54:09, Nicolas Zea wrote:

[Nicolas Zea, 2014/05/08 21:43:09]

Is this something we want to enforce at the client though? This seems like a
strange detail to have here, and likely something that could be enforced at the
server.

[haitaol1, 2014/05/09 16:55:58]

How can server enforce this given that backup backend never contacts server?

On 2014/05/08 21:43:09, Nicolas Zea wrote:

[Nicolas Zea, 2014/05/13 17:39:10]

The command to roll back in the first place comes from the server, and should
never be sent to a managed user, right?

On 2014/05/09 16:55:58, haitaol1 wrote:

[haitaol1, 2014/05/13 18:08:22]

That's right. But we shouldn't start backup for managed users because that would
stop normal syncing. Normally if sync is on, SigninManagerBase returns non-empty
user name. But for managed user, it returns empty string (at least it used to
be, there was actually a DCHECK for that). Using SigninManagerBase, normal sync
could be trumped by backup.

On 2014/05/13 17:39:10, Nicolas Zea wrote:

[Nicolas Zea, 2014/05/14 23:17:56]

Ah, now I understand. Could you add a comment explaining this then?

On 2014/05/13 18:08:22, haitaol1 wrote:

[haitaol1, 2014/05/14 23:49:27]

Commented on |signin_| in .h

On 2014/05/14 23:17:56, Nicolas Zea wrote:

+                           base::Closure start_backup,
+                           base::Closure start_rollback);
+  ~BackupRollbackController();
+
+  // Check to see whether to start backup/rollback.
+  void Reset(base::TimeDelta delay);

[Nicolas Zea, 2014/05/06 18:54:09]

This isn't actually resetting anything right? Perhaps call this Start? Also,
comment what |delay| is for.

[haitaol1, 2014/05/07 21:34:17]

Done.

+
+  // Update rollback preference to indicate rollback is needed.
+  void OnRollbackReceived();
+
+  // Update rollback preference to indicate rollback is finished.
+  void OnRollbackDone();
+
+ private:
+  // Check signin status and rollback preference and start backup/rollback
+  // accordingly.
+  void TryStart();
+
+  sync_driver::SyncPrefs* sync_prefs_;
+  const ManagedUserSigninManagerWrapper* signin_;
+  base::Closure start_backup_;
+  base::Closure start_rollback_;
+  base::WeakPtrFactory<BackupRollbackController> weak_ptr_factory_;

[Nicolas Zea, 2014/05/06 18:54:09]

disallow copy and assign

[haitaol1, 2014/05/07 21:34:17]

Done.

+};
+
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_BACKUP_ROLLBACK_CONTROLLER_H_