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

chrome/browser/sync/engine/syncer_util.h

 // 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.
 //
 // Utility functions manipulating syncable::Entries, intended for use by the
 // syncer.
 
 #ifndef CHROME_BROWSER_SYNC_ENGINE_SYNCER_UTIL_H_
 #define CHROME_BROWSER_SYNC_ENGINE_SYNCER_UTIL_H_
 #pragma once
@@ skipping 58 matching lines @@
                              const syncable::Id& id);
 
   static bool ServerAndLocalEntriesMatch(syncable::Entry* entry);
 
   static void SplitServerInformationIntoNewEntry(
       syncable::WriteTransaction* trans,
       syncable::MutableEntry* entry);
 
   // This function is called on an entry when we can update the user-facing data
   // from the server data.
-  static void UpdateLocalDataFromServerData(syncable::WriteTransaction* trans,
+  static bool UpdateLocalDataFromServerData(syncable::WriteTransaction* trans,
                                             syncable::MutableEntry* entry);
 
   static VerifyCommitResult ValidateCommitEntry(syncable::Entry* entry);
 
   static VerifyResult VerifyNewEntry(const SyncEntity& update,
                                      syncable::Entry* target,
                                      const bool deleted);
 
   // Assumes we have an existing entry; check here for updates that break
   // consistency rules.
@@ skipping 45 matching lines @@
   // if they match.  For an up-to-date item, this should be the case.
   static bool ServerAndLocalOrdersMatch(syncable::Entry* entry);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(SyncerUtil);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_ENGINE_SYNCER_UTIL_H_