This is commit is just the output of running the syntax updater on the
files in the internal/compiler/widgets directory.
No extra manual steps were done.
Note: In order to run the updater, I did a hack so that the updater wouldn't
choke on internal item used by the styles by commenting out the check in
ElementType::lookup_type_for_child_element
This is not supported right now, the other elements will not be part of
the layout, and two `for` will be in the same listview, creating bad
situation with the scrollbar.
This is a warning since it would be a breaking change to make it an
error.
For example, we used a FocusScope in the StandardListView implementation so
I had to go trough one level of indirection
CC: #860
