Persist offline page info in a navigation entry if needed

components/sessions/core/serialized_navigation_entry.cc

Index: components/sessions/core/serialized_navigation_entry.cc
diff --git a/components/sessions/core/serialized_navigation_entry.cc b/components/sessions/core/serialized_navigation_entry.cc
index 4f4124c598a5e7c50be2ed812a71946ec0aa6b33..02139965c445f9757dadd9b1bae718f0597034b3 100644
--- a/components/sessions/core/serialized_navigation_entry.cc
+++ b/components/sessions/core/serialized_navigation_entry.cc
@@ -182,6 +182,17 @@ void WriteString16ToPickle(base::Pickle* pickle,
   }
 }
 
+void WriteStringMapToPickle(base::Pickle* pickle,
+                            int* bytes_written,
+                            int max_bytes,
+                            const std::map<std::string, std::string>& map) {
+  pickle->WriteInt(map.size());
+  for (const auto entry : map) {
+    WriteStringToPickle(pickle, bytes_written, max_bytes, entry.first);
+    WriteStringToPickle(pickle, bytes_written, max_bytes, entry.second);
+  }
+}
+
 // A mask used for arbitrary boolean values needed to represent a
 // NavigationEntry. Currently only contains HAS_POST_DATA.
 //
@@ -213,6 +224,7 @@ enum TypeMask {
 // search_terms_
 // http_status_code_
 // referrer_policy_
+// extended_info_map_
 
 void SerializedNavigationEntry::WriteToPickle(int max_size,
                                               base::Pickle* pickle) const {
@@ -257,6 +269,8 @@ void SerializedNavigationEntry::WriteToPickle(int max_size,
   pickle->WriteInt(http_status_code_);
 
   pickle->WriteInt(referrer_policy_);
+
+  WriteStringMapToPickle(pickle, &bytes_written, max_size, extended_info_map_);
 }
 
 bool SerializedNavigationEntry::ReadFromPickle(base::PickleIterator* iterator) {
@@ -335,6 +349,19 @@ bool SerializedNavigationEntry::ReadFromPickle(base::PickleIterator* iterator) {
           SerializedNavigationDriver::Get()->StripReferrerFromPageState(
               encoded_page_state_);
     }
+
+    int extended_info_map_size = 0;
+    if (iterator->ReadInt(&extended_info_map_size) &&
+        extended_info_map_size >= 0) {
+      for (int i = 0; i < extended_info_map_size; ++i) {
+        std::string key;
+        std::string value;
+        if (iterator->ReadString(&key) && iterator->ReadString(&value))
+          extended_info_map_[key] = value;
+      }
+    } else {
+      extended_info_map_.clear();
+    }
   }
 
   SerializedNavigationDriver::Get()->Sanitize(this);