[OfflinePages] RequestCoordinatorFactory return null for incognito

chrome/browser/net/net_error_tab_helper.cc

Index: chrome/browser/net/net_error_tab_helper.cc
diff --git a/chrome/browser/net/net_error_tab_helper.cc b/chrome/browser/net/net_error_tab_helper.cc
index 823d96fd9a59b8d287529321bd40321bb0be47ea..8015b770b916241f3599cd5e710657c35e44ebdf 100644
--- a/chrome/browser/net/net_error_tab_helper.cc
+++ b/chrome/browser/net/net_error_tab_helper.cc
@@ -281,6 +281,7 @@ void NetErrorTabHelper::DownloadPageLaterHelper(const GURL& page_url) {
   offline_pages::RequestCoordinator* request_coordinator =
       offline_pages::RequestCoordinatorFactory::GetForBrowserContext(
           web_contents()->GetBrowserContext());
+  DCHECK(request_coordinator) << "No RequestCoordinator for SavePageLater";
   offline_pages::ClientId client_id(
       offline_pages::kAsyncNamespace, base::GenerateGUID());
   request_coordinator->SavePageLater(