[Sync] USS: Ignore encryption changes during conflict resolution 1/2

sync/api/conflict_resolution.h

 // Copyright 2016 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.
 
 #ifndef SYNC_API_CONFLICT_RESOLUTION_H_
 #define SYNC_API_CONFLICT_RESOLUTION_H_
 
 #include <memory>
 
 #include "sync/api/entity_data.h"
 
 namespace syncer_v2 {
 
 // A simple class to represent the resolution of a data conflict. We either:
 // 1) Use the local client data and update the server.
 // 2) Use the remote server data and update the client.
 // 3) Use newly created data and update both.
 class SYNC_EXPORT ConflictResolution {
  public:
   // This enum is used in histograms.xml and entries shouldn't be renumbered or
   // removed. New entries must be added at the end, before TYPE_SIZE.
   enum Type {
     CHANGES_MATCH,  // Exists for logging purposes.
     USE_LOCAL,
     USE_REMOTE,
     USE_NEW,
+    IGNORE_LOCAL_ENCRYPTION,   // Exists for logging purposes.
+    IGNORE_REMOTE_ENCRYPTION,  // Exists for logging purposes.
     TYPE_SIZE,
   };
 
   // Convenience functions for brevity.
   static ConflictResolution UseLocal();
   static ConflictResolution UseRemote();
   static ConflictResolution UseNew(std::unique_ptr<EntityData> data);
 
   // Move constructor since we can't copy a unique_ptr.
   ConflictResolution(ConflictResolution&& other);
   ~ConflictResolution();
 
   Type type() const { return type_; }
 
   // Get the data for USE_NEW, or nullptr. Can only be called once.
   std::unique_ptr<EntityData> ExtractData();
 
  private:
   ConflictResolution(Type type, std::unique_ptr<EntityData> data);
 
   const Type type_;
   std::unique_ptr<EntityData> data_;
 
   DISALLOW_COPY_AND_ASSIGN(ConflictResolution);
 };
 
 }  // namespace syncer_v2
 
 #endif  // SYNC_API_CONFLICT_RESOLUTION_H_