Get signals working in the EXTRA_DATA section of MHTML

chrome/browser/android/offline_pages/offline_page_bridge.cc

Index: chrome/browser/android/offline_pages/offline_page_bridge.cc
diff --git a/chrome/browser/android/offline_pages/offline_page_bridge.cc b/chrome/browser/android/offline_pages/offline_page_bridge.cc
index 15bef35435b9f7eea105177292f9610048324f80..62ffe7fa098e566d4da5a89030f9e19d6f5187dc 100644
--- a/chrome/browser/android/offline_pages/offline_page_bridge.cc
+++ b/chrome/browser/android/offline_pages/offline_page_bridge.cc
@@ -449,8 +449,10 @@ void OfflinePageBridge::SavePage(
   save_page_params.client_id.id = ConvertJavaStringToUTF8(env, j_client_id);
   save_page_params.is_background = false;
 
+  std::string signal_data;
+
   offline_page_model_->SavePage(
-      save_page_params, std::move(archiver),
+      save_page_params, std::move(archiver), signal_data,
       base::Bind(&SavePageCallback, j_callback_ref, save_page_params.url));
 }