[Sync] Logic in ProfileSyncService to orchestrate clearing server data during passphrase transition

After user switches to custom passphrase encryption a set of steps needs to be performed:
1. Download all latest updates from server (catch up configure).
2. Clear user data on server.
3. Clear directory and restart sync so that data from model types is recommitted
   with new encryption.

1. is done by calling DataTypeManager::Configure(CONFIGURE_REASON_CATCH_UP).
It will discard local changes, unapply remote changes, download updates and
trigger model association. This will ensure that model types are up to date with
server data. Retry logic in sync engine will ensure this step is retried until
it completes. Upon completion OnConfigureDone is called.

2. is done by sending ClientToServerMessage with ClearServerDataMessage. Retry
logic in sync engine ensures this request is delivered successfully.

3. is done with call to ShutdownImpl(syncer::DISABLE_SYNC) which deletes sync
directory database.

If browser is terminated at any point, transition process should be restarted.
For this new Nigori state and flag that transition is in progress is saved in
preferences.

BUG=490836
R=zea@chromium.org

Review URL: https://codereview.chromium.org/1313603005

Cr-Commit-Position: refs/heads/master@{#346185}

1 files changed, 0 insertions, 4 deletions

diff --git a/sync/internal_api/sync_encryption_handler_impl.h b/sync/internal_api/sync_encryption_handler_impl.h
index bb2a0e5..b621484 100644
--- a/sync/internal_api/sync_encryption_handler_impl.h
+++ b/sync/internal_api/sync_encryption_handler_impl.h
@@ -276,10 +276,6 @@ class SYNC_EXPORT_PRIVATE SyncEncryptionHandlerImpl
   // Notify observers when a custom passphrase is set by this device.
   void NotifyObserversOfLocalCustomPassphrase(WriteTransaction* trans);
 
-  // Update the Nigori node to indicate that we're transitioning to passphrsae
-  // encryption.
-  void UpdateNigoriForTransitionToPassphraseEncryption(WriteTransaction* trans);
-
   base::ThreadChecker thread_checker_;
 
   base::ObserverList<SyncEncryptionHandler::Observer> observers_;