[Sync] Add ability to save/restore Nigori to SyncEncryptionHandlerImpl

sync/internal_api/sync_manager_impl_unittest.cc

Index: sync/internal_api/sync_manager_impl_unittest.cc
diff --git a/sync/internal_api/sync_manager_impl_unittest.cc b/sync/internal_api/sync_manager_impl_unittest.cc
index 41b2e2df4b812fe06aa8eac08a32809131e66088..69480442a0d6c41ed520ba8b8bad9d1d0b9df92c 100644
--- a/sync/internal_api/sync_manager_impl_unittest.cc
+++ b/sync/internal_api/sync_manager_impl_unittest.cc
@@ -817,6 +817,8 @@ class SyncEncryptionHandlerObserverMock
   MOCK_METHOD1(OnCryptographerStateChanged, void(Cryptographer*));  // NOLINT
   MOCK_METHOD2(OnPassphraseTypeChanged, void(PassphraseType,
                                              base::Time));  // NOLINT
+  MOCK_METHOD1(OnLocalSetCustomPassphrase,
+               void(const SyncEncryptionHandler::NigoriState&));  // NOLINT
 };
 
 }  // namespace