[Sync] Add keystore migration conflict support.

sync/internal_api/sync_encryption_handler_impl.h

 // 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.
 
 #ifndef SYNC_INTERNAL_API_SYNC_ENCRYPTION_HANDLER_IMPL_H_
 #define SYNC_INTERNAL_API_SYNC_ENCRYPTION_HANDLER_IMPL_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 98 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(SyncEncryptionHandlerImplTest,
                            SetKeystoreAfterReceivingMigratedNigori);
   FRIEND_TEST_ALL_PREFIXES(SyncEncryptionHandlerImplTest,
                            SetCustomPassAfterMigration);
   FRIEND_TEST_ALL_PREFIXES(SyncEncryptionHandlerImplTest,
                            SetCustomPassAfterMigrationNoKeystoreKey);
   FRIEND_TEST_ALL_PREFIXES(SyncEncryptionHandlerImplTest,
                            SetImplicitPassAfterMigrationNoKeystoreKey);
   FRIEND_TEST_ALL_PREFIXES(SyncEncryptionHandlerImplTest,
                            MigrateOnEncryptEverythingKeystorePassphrase);
+  FRIEND_TEST_ALL_PREFIXES(SyncEncryptionHandlerImplTest,
+                           ReceiveMigratedNigoriWithOldPassphrase);
 
   // Container for members that require thread safety protection.  All members
   // that can be accessed from more than one thread should be held here and
   // accessed via UnlockVault(..) and UnlockVaultMutable(..), which enforce
   // that a transaction is held.
   struct Vault {
     Vault(Encryptor* encryptor, ModelTypeSet encrypted_types);
     ~Vault();
 
     // Sync's cryptographer. Used for encrypting and decrypting sync data.
@@ skipping 158 matching lines @@
 
   // The time (in ms) the nigori was migrated to support keystore encryption.
   int64 migration_time_ms_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncEncryptionHandlerImpl);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_SYNC_ENCRYPTION_HANDLER_IMPL_H_