One approach is the difference of row numbers:
select name, count(*)
from (select t.*,
(row_number() over (order by id) -
row_number() over (partition by name order by id)
) as grp
from t
) t
group by grp, name;
The logic is easiest to understand if you run the subquery and look at the values of each row number separately and then look at the difference.