Introduce the plumbing necessary to report Unrecoverable error from model safe workers.

chrome/browser/sync/engine/model_changing_syncer_command.cc

 // Copyright (c) 2011 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/engine/model_changing_syncer_command.h"
 
 #include "base/callback_old.h"
 #include "chrome/browser/sync/engine/model_safe_worker.h"
 #include "chrome/browser/sync/sessions/status_controller.h"
 #include "chrome/browser/sync/sessions/sync_session.h"
+#include "chrome/browser/sync/sessions/unrecoverable_error_info.h"
 
 namespace browser_sync {
+using sessions::UnrecoverableErrorInfo;
 
 void ModelChangingSyncerCommand::ExecuteImpl(sessions::SyncSession* session) {
   work_session_ = session;
   if (!ModelNeutralExecuteImpl(work_session_)) {
     return;
   }
 
   // Project the list of active types (i.e., types in the routing
   // info) to a list of groups.
   //
@@ skipping 15 matching lines @@
     ModelSafeGroup group = worker->GetModelSafeGroup();
     // Skip workers whose group isn't active.
     if (active_groups.find(group) == active_groups.end()) {
       VLOG(2) << "Skipping worker for group "
               << ModelSafeGroupToString(group);
       continue;
     }
 
     sessions::StatusController* status = work_session_->status_controller();
     sessions::ScopedModelSafeGroupRestriction r(status, group);
-    scoped_ptr<Callback0::Type> c(NewCallback(this,
-        &ModelChangingSyncerCommand::StartChangingModel));
-    worker->DoWorkAndWaitUntilDone(c.get());

[akalin, 2011/10/26 00:25:05]

Add a comment saying that it's safe to use Unretained here, since we block until
after the callback is called.

[lipalani1, 2011/10/26 01:39:11]

Done.

+    WorkCallback c = base::Bind(
+        &ModelChangingSyncerCommand::StartChangingModel,
+        base::Unretained(this));
+
+    UnrecoverableErrorInfo error_info = worker->DoWorkAndWaitUntilDone(c);

[akalin, 2011/10/26 00:25:05]

this will probably trigger a compiler warning/error since you're not using it.

#include basictypes.h and do:

// TODO(lipalani): Check the return value for an unrecoverable error ...
ignore_result(worker->DoWorkAndWiatUntilDone(c));

[lipalani1, 2011/10/26 01:39:11]

Done.

+
+    // TODO(lipalani): Check if there is an unrecoverable error from error_info
+    // and do apropriate actions.
   }
 }
 
 bool ModelChangingSyncerCommand::ModelNeutralExecuteImpl(
     sessions::SyncSession* session) {
   return true;
 }
 
 }  // namespace browser_sync