This is a speculative fix for subprocess being unable to find
string-escape later in execution; the theory being that something
(unclear what) is interfering w/ codecs' lookup logic and that calling
lookup earlier would allow string-escape to be cached before any such
interference. See crbug.com/912292#c2 for more.

Bug: 912292
Change-Id: I0abdd394253c9a4984db7c6c81d044087edc68fd
Reviewed-on: https://chromium-review.googlesource.com/c/1363753Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>