Implement a bag of chips for sync.

sync/engine/model_changing_syncer_command.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 "sync/engine/model_changing_syncer_command.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "sync/engine/syncer_proto_util.h"
 #include "sync/sessions/status_controller.h"
 #include "sync/sessions/sync_session.h"
 
 namespace syncer {
 
 SyncerError ModelChangingSyncerCommand::ExecuteImpl(
     sessions::SyncSession* session) {
   work_session_ = session;
   SyncerError result = SYNCER_OK;
 
@@ skipping 18 matching lines @@
         // unretained.
         base::Unretained(this));
 
     SyncerError this_worker_result = worker->DoWorkAndWaitUntilDone(c);
     // TODO(rlarocque): Figure out a better way to deal with errors from
     // multiple models at once.  See also: crbug.com/109422.
     if (this_worker_result != SYNCER_OK)
       result = this_worker_result;
   }
 
+  if (result == SYNCER_OK) {
+    // In case of success, persist an eventul bag of chips.
+    SyncerProtoUtil::PersistBagOfChips(session->context()->directory(),

[Nicolas Zea, 2012/09/07 18:38:43]

we actually want to be able to persist the bag of chips even if the request
failed (it's still useful to let the server track client state even if it's
throttling for example)

Additionally, this is getting run on every command, and there are reallly only
two commands that interact with the sync server. I'd rather have this call
explicitly in those two commands.

[qsr, 2012/09/10 08:12:37]

 And I was missing one of the 2. Thanks.

 On the other hand, to have this work, I have to override the ExecuteImpl method
-> The other method is called one for each worker... Which mean that it doesn't
work if there is no worker (won't happen I guess, but still), but will be called
more than once if there is more than one worker.

+        session->status_controller().updates_response());
+  }
+
   return result;
 }
 
 }  // namespace syncer