[Sync] Refactor sync datatype error handling.

chrome/browser/sync/glue/extension_model_associator.h

Index: chrome/browser/sync/glue/extension_model_associator.h
diff --git a/chrome/browser/sync/glue/extension_model_associator.h b/chrome/browser/sync/glue/extension_model_associator.h
index b71a281655907633ac8050c9ff011ce08683a780..48f51b21426598cd4286434052b1e6412b8ba7e1 100644
--- a/chrome/browser/sync/glue/extension_model_associator.h
+++ b/chrome/browser/sync/glue/extension_model_associator.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include "base/basictypes.h"
+#include "chrome/browser/sync/api/sync_error.h"
 #include "chrome/browser/sync/glue/extension_sync_traits.h"
 #include "chrome/browser/sync/glue/model_associator.h"
 #include "chrome/browser/sync/syncable/model_type.h"
@@ -32,8 +33,8 @@ class ExtensionModelAssociator : public AssociatorInterface {
   static syncable::ModelType model_type() { return syncable::EXTENSIONS; }
 
   // AssociatorInterface implementation.
-  virtual bool AssociateModels();
-  virtual bool DisassociateModels();
+  virtual bool AssociateModels(SyncError* error);
+  virtual bool DisassociateModels(SyncError* error);
   virtual bool SyncModelHasUserCreatedNodes(bool* has_nodes);
   virtual void AbortAssociation();
   virtual bool CryptoReadyIfNecessary();