Persist offline page info in a navigation entry if needed

chrome/browser/android/offline_pages/offline_page_info_handler.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_OFFLINE_PAGE_INFO_HANDLER_H_
+#define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_INFO_HANDLER_H_
+
+#include "components/sessions/content/extended_info_handler.h"
+
+namespace offline_pages {
+
+// Used to parse the extra request header string that defines offline page
+// loading behaviors.
+//
+class OfflinePageInfoHandler : public sessions::ExtendedInfoHandler {
+ public:
+  // Creates and registers a single instance.
+  static void Register();
+
+  OfflinePageInfoHandler();
+  ~OfflinePageInfoHandler() override;
+
+  // ExtendedInfoHandler:
+  std::string GetExtendedInfo(
+      const content::NavigationEntry& entry) const override;
+  void RestoreExtendedInfo(const std::string& info,
+                           content::NavigationEntry* entry) override;
+};
+
+}  // namespace offline_pages
+
+#endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_INFO_HANDLER_H_