Persist offline page info in a navigation entry if needed

components/sessions/content/content_serialized_navigation_driver.cc

Index: components/sessions/content/content_serialized_navigation_driver.cc
diff --git a/components/sessions/content/content_serialized_navigation_driver.cc b/components/sessions/content/content_serialized_navigation_driver.cc
index a3305a8695311157429112f3677d91fa124daac5..c20cd895f61c036c4147cc9c8af3d0d8e5276ef8 100644
--- a/components/sessions/content/content_serialized_navigation_driver.cc
+++ b/components/sessions/content/content_serialized_navigation_driver.cc
@@ -6,6 +6,7 @@
 
 #include "base/memory/singleton.h"
 #include "build/build_config.h"
+#include "components/sessions/content/extended_info_handler.h"
 #include "components/sessions/core/serialized_navigation_entry.h"
 #include "content/public/common/page_state.h"
 #include "content/public/common/referrer.h"
@@ -133,4 +134,16 @@ std::string ContentSerializedNavigationDriver::StripReferrerFromPageState(
       .ToEncodedData();
 }
 
+void ContentSerializedNavigationDriver::RegisterExtendedInfoHandler(
+    const std::string& key,
+    std::unique_ptr<ExtendedInfoHandler> handler) {
+  DCHECK(!key.empty());

[sky, 2016/09/29 03:08:19]

Please also add a DCHECK that there isn't a handler registered for key already
and that handler.get() is non-null.

[jianli, 2016/09/29 22:02:29]

Done.

+  extended_info_handler_map_[key] = std::move(handler);
+}
+
+const ContentSerializedNavigationDriver::ExtendedInfoHandlerMap&
+ContentSerializedNavigationDriver::GetAllExtendedInfoHandlers() const {
+  return extended_info_handler_map_;
+}
+
 }  // namespace sessions