Revert "Updated ownership of NavigationItems within CRWSessionController."

ios/web/navigation/navigation_item_impl_list.mm

Index: ios/web/navigation/navigation_item_impl_list.mm
diff --git a/ios/web/navigation/navigation_item_impl_list.mm b/ios/web/navigation/navigation_item_impl_list.mm
index 03d4c8728e48a566f45cf31cfdeebcc32aa09a51..22d58130ca3450eaa1c54e8980ecb1f407251cf1 100644
--- a/ios/web/navigation/navigation_item_impl_list.mm
+++ b/ios/web/navigation/navigation_item_impl_list.mm
@@ -19,13 +19,4 @@ ScopedNavigationItemImplList CreateScopedNavigationItemImplList(
   return list;
 }
 
-NavigationItemList CreateNavigationItemList(
-    ScopedNavigationItemImplList& scoped_item_list) {
-  NavigationItemList list(scoped_item_list.size());
-  for (size_t index = 0; index < scoped_item_list.size(); ++index) {
-    list[index] = scoped_item_list[index].get();
-  }
-  return list;
-}
-
 }  // namespace web