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

chrome/browser/sync/engine/update_applicator.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.
 //
 // An UpdateApplicator is used to iterate over a number of unapplied updates,
 // applying them to the client using the given syncer session.
 //
 // UpdateApplicator might resemble an iterator, but it actually keeps retrying
 // failed updates until no remaining updates can be successfully applied.
 
@@ skipping 37 matching lines @@
   bool AllUpdatesApplied() const;
 
   // This class does not automatically save its progress into the
   // SyncSession -- to get that to happen, call this method after update
   // application is finished (i.e., when AttemptOneAllocation stops returning
   // true).
   void SaveProgressIntoSessionState(
       sessions::ConflictProgress* conflict_progress,
       sessions::UpdateProgress* update_progress);
 
+  bool failed_update() const;
+
  private:
   // Track the status of all applications.
   // We treat encryption conflicts as nonblocking conflict items when we save
   // progress.
   class ResultTracker {
    public:
      explicit ResultTracker(size_t num_results);
      virtual ~ResultTracker();
      void AddConflict(syncable::Id);
      void AddEncryptionConflict(syncable::Id);
      void AddSuccess(syncable::Id);
      void SaveProgress(sessions::ConflictProgress* conflict_progress,
                        sessions::UpdateProgress* update_progress);
      void ClearConflicts();
+     void set_failed_update();
+     bool failed_udpate() const;
 
      // Returns true iff conflicting_ids_ is empty. Does not check
      // encryption_conflict_ids_.
      bool no_conflicts() const;
    private:
     std::vector<syncable::Id> conflicting_ids_;
     std::vector<syncable::Id> successful_ids_;
     std::vector<syncable::Id> encryption_conflict_ids_;
+    bool failed_update_;
   };
 
   // If true, AttemptOneApplication will skip over |entry| and return true.
   bool SkipUpdate(const syncable::Entry& entry);
 
   // Adjusts the UpdateIterator members to move ahead by one update.
   void Advance();
 
   // Used to resolve conflicts when trying to apply updates.
   ConflictResolver* const resolver_;
@@ skipping 11 matching lines @@
 
   // Track the result of the attempts to update applications.
   ResultTracker application_results_;
 
   DISALLOW_COPY_AND_ASSIGN(UpdateApplicator);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_ENGINE_UPDATE_APPLICATOR_H_