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

chrome/browser/sync/glue/sync_backend_host_impl.h

Index: chrome/browser/sync/glue/sync_backend_host_impl.h
diff --git a/chrome/browser/sync/glue/sync_backend_host_impl.h b/chrome/browser/sync/glue/sync_backend_host_impl.h
index 57d99ece4d6c96e4b257bc22b7967ee9af4d9981..ba93265f32379bc8eed497b2e2227748f45e8aa1 100644
--- a/chrome/browser/sync/glue/sync_backend_host_impl.h
+++ b/chrome/browser/sync/glue/sync_backend_host_impl.h
@@ -279,6 +279,9 @@ class SyncBackendHostImpl
       syncer::PassphraseType type,
       base::Time explicit_passphrase_time);
 
+  void HandleLocalSetCustomPassphraseOnFrontendLoop(
+      const syncer::SyncEncryptionHandler::NigoriState& nigori_state);
+
   void HandleStopSyncingPermanentlyOnFrontendLoop();
 
   // Dispatched to from OnConnectionStatusChange to handle updating
@@ -361,4 +364,3 @@ class SyncBackendHostImpl
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_IMPL_H_
-