Fix Opera test failures by reverting unnecessary part of 583508e.

Opera seems to have some consistent but difficult to diagnose bugs related to
using _.map in this context. (As in, minifying the test was difficult because
there seemed to be some odd action at a distance, but a given test failure was
fully reproducible.) This appears to work while still preserving the feature
added in 583508e.

Also fix a missing var (which does not appear to be the original problem).