Add return values to SyncerCommand

chrome/browser/sync/engine/syncer_command.h

Index: chrome/browser/sync/engine/syncer_command.h
diff --git a/chrome/browser/sync/engine/syncer_command.h b/chrome/browser/sync/engine/syncer_command.h
index 2aad6530b4c0decc709be09009cb7f95d7db407d..024bbae2b1d6e1e15fe992dc9a47a1fa44c9851f 100644
--- a/chrome/browser/sync/engine/syncer_command.h
+++ b/chrome/browser/sync/engine/syncer_command.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -8,6 +8,8 @@
 
 #include "base/basictypes.h"
 
+#include "chrome/browser/sync/internal_api/includes/syncer_error.h"
+
 namespace browser_sync {
 
 namespace sessions {
@@ -32,10 +34,10 @@ class SyncerCommand {
   virtual ~SyncerCommand();
 
   // Execute dispatches to a derived class's ExecuteImpl.
-  void Execute(sessions::SyncSession* session);
+  SyncerError Execute(sessions::SyncSession* session);
 
   // ExecuteImpl is where derived classes actually do work.
-  virtual void ExecuteImpl(sessions::SyncSession* session) = 0;
+  virtual SyncerError ExecuteImpl(sessions::SyncSession* session) = 0;
  private:
   void SendNotifications(sessions::SyncSession* session);
   DISALLOW_COPY_AND_ASSIGN(SyncerCommand);