[SyncFS] Restore refresh token availability on re-initialize of SyncEngine

chrome/browser/sync_file_system/drive_backend/sync_engine.cc

Index: chrome/browser/sync_file_system/drive_backend/sync_engine.cc
diff --git a/chrome/browser/sync_file_system/drive_backend/sync_engine.cc b/chrome/browser/sync_file_system/drive_backend/sync_engine.cc
index ac005612baf7351b58cc4b535881af1ac5299b32..6e082ea1fc48ab14955cc0b5598ae4d7bc8dc84b 100644
--- a/chrome/browser/sync_file_system/drive_backend/sync_engine.cc
+++ b/chrome/browser/sync_file_system/drive_backend/sync_engine.cc
@@ -354,6 +354,10 @@ void SyncEngine::InitializeInternal(
   service_state_ = REMOTE_SERVICE_TEMPORARY_UNAVAILABLE;
   SetSyncEnabled(sync_enabled_);
   OnNetworkChanged(net::NetworkChangeNotifier::GetConnectionType());
+  if (drive_service_->HasRefreshToken())
+    OnReadyToSendRequests();
+  else
+    OnRefreshTokenInvalid();
 }
 
 void SyncEngine::AddServiceObserver(SyncServiceObserver* observer) {