Expose local sync mode status in the chrome://sync-internals page.

components/sync/engine_impl/sync_manager_impl.cc

Index: components/sync/engine_impl/sync_manager_impl.cc
diff --git a/components/sync/engine_impl/sync_manager_impl.cc b/components/sync/engine_impl/sync_manager_impl.cc
index a237ea971109acd1d86d249d754a61f170e99158..e52090e8b2f7ffb56c0e841a10f43fce067e233c 100644
--- a/components/sync/engine_impl/sync_manager_impl.cc
+++ b/components/sync/engine_impl/sync_manager_impl.cc
@@ -277,6 +277,8 @@ void SyncManagerImpl::Init(InitArgs* args) {
 
   if (args->enable_local_sync_backend) {
     VLOG(1) << "Running against local sync backend.";
+    allstatus_.SetLocalBackendFolder(
+        args->local_sync_backend_folder.AsUTF8Unsafe());
     connection_manager_ = base::MakeUnique<LoopbackConnectionManager>(
         args->cancelation_signal, args->local_sync_backend_folder);
   } else {