Persist offline page info in a navigation entry if needed

components/sessions/content/content_serialized_navigation_driver.cc

 // Copyright 2014 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.
 
 #include "components/sessions/content/content_serialized_navigation_driver.h"
 
 #include "base/memory/singleton.h"
 #include "build/build_config.h"
 #include "components/sessions/core/serialized_navigation_entry.h"
 #include "content/public/common/page_state.h"
@@ skipping 115 matching lines @@
 #endif  // defined(OS_ANDROID)
 }
 
 std::string ContentSerializedNavigationDriver::StripReferrerFromPageState(
       const std::string& page_state) const {
   return content::PageState::CreateFromEncodedData(page_state)
       .RemoveReferrer()
       .ToEncodedData();
 }
 
+void ContentSerializedNavigationDriver::RegisterExtendedInfoHandler(
+    const std::string& key,
+    std::unique_ptr<ExtendedInfoHandler> handler) {
+  DCHECK(!key.empty());
+  DCHECK(!extended_info_handler_map_.count(key));
+  DCHECK(handler.get());
+  extended_info_handler_map_[key] = std::move(handler);
+}
+
+const ContentSerializedNavigationDriver::ExtendedInfoHandlerMap&
+ContentSerializedNavigationDriver::GetAllExtendedInfoHandlers() const {
+  return extended_info_handler_map_;
+}
+
 }  // namespace sessions