Get signals working in the EXTRA_DATA section of MHTML

chrome/browser/android/offline_pages/background_loader_offliner.cc

Index: chrome/browser/android/offline_pages/background_loader_offliner.cc
diff --git a/chrome/browser/android/offline_pages/background_loader_offliner.cc b/chrome/browser/android/offline_pages/background_loader_offliner.cc
index 89d11b6df9f7a9ae0c280b15480b0b409a7355cb..5e93fdff823ee9f151666b3b364904e29597a0e7 100644
--- a/chrome/browser/android/offline_pages/background_loader_offliner.cc
+++ b/chrome/browser/android/offline_pages/background_loader_offliner.cc
@@ -140,8 +140,9 @@ void BackgroundLoaderOffliner::DidStopLoading() {
   params.client_id = request.client_id();
   params.proposed_offline_id = request.request_id();
   params.is_background = true;
+  std::vector<std::string> signal_data;
   offline_page_model_->SavePage(
-      params, std::move(archiver),
+      params, std::move(archiver), signal_data,
       base::Bind(&BackgroundLoaderOffliner::OnPageSaved,
                  weak_ptr_factory_.GetWeakPtr()));
 }