Get signals working in the EXTRA_DATA section of MHTML

chrome/browser/android/offline_pages/prerendering_offliner.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_ANDROID_OFFLINE_PAGES_PRERENDERING_OFFLINER_H_
 #define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_PRERENDERING_OFFLINER_H_
 
 #include <memory>
 
 #include "base/android/application_status_listener.h"
@@ skipping 54 matching lines @@
   // Callback logic for PrerenderingLoader::LoadPage().
   void OnLoadPageDone(const SavePageRequest& request,
                       Offliner::RequestStatus load_status,
                       content::WebContents* web_contents);
 
   // Callback logic for OfflinePageModel::SavePage().
   void OnSavePageDone(const SavePageRequest& request,
                       SavePageResult save_result,
                       int64_t offline_id);
 
+  // Write the payload of the loading signal data MHTML section into a string.
+  std::string SerializeLoadingSignalData();
+
   PrerenderingLoader* GetOrCreateLoader();
 
   // Listener function for changes to application background/foreground state.
   void OnApplicationStateChange(
       base::android::ApplicationState application_state);
   void HandleApplicationStateChangeCancel(const SavePageRequest& request,
                                           int64_t offline_id);
 
   // Not owned.
   content::BrowserContext* browser_context_;
@@ skipping 14 matching lines @@
   // ApplicationStatusListener to monitor if the Chrome moves to the foreground.
   std::unique_ptr<base::android::ApplicationStatusListener> app_listener_;
   base::WeakPtrFactory<PrerenderingOffliner> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderingOffliner);
 };
 
 }  // namespace offline_pages
 
 #endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_PRERENDERING_OFFLINER_H_