Fix the Regexp::FactorAlternation*() argument names.
Fix the Regexp::FactorAlternation*() argument names.

Change-Id: Ic6329dd93f5e9da2ac53b8b1862a3f38590c485c
Reviewed-on: https://code-review.googlesource.com/20771
Reviewed-by: Paul Wankadia <62d4e38bb1380f055ec4b899baa75e52af09c5f7@google.com>

google/re2,google/re2,google/re2,google/re2,google/re2