Ntp: restore scroll position.

content/browser/frame_host/navigation_entry_impl.cc

Index: content/browser/frame_host/navigation_entry_impl.cc
diff --git a/content/browser/frame_host/navigation_entry_impl.cc b/content/browser/frame_host/navigation_entry_impl.cc
index 31b1d508e8ee0a7f70a5fdbc9a28b5e169c5d57e..02c1c024155c4eab6708b7b558fa176bd253aeb5 100644
--- a/content/browser/frame_host/navigation_entry_impl.cc
+++ b/content/browser/frame_host/navigation_entry_impl.cc
@@ -582,6 +582,12 @@ bool NavigationEntryImpl::GetExtraData(const std::string& key,
   return true;
 }
 
+void NavigationEntryImpl::GetExtraData(
+    std::map<std::string, base::string16>* data) {
+  for (const auto& entry : extra_data_)
+    (*data)[entry.first] = entry.second;
+}
+
 void NavigationEntryImpl::ClearExtraData(const std::string& key) {
   extra_data_.erase(key);
 }