Make sure there is text output when converting from PDF to PS for text
with negative size, which should be rendered rotated 180 degrees with
respect to the origin.

BUG=806746,827748

Change-Id: Ia214f25f8fdb945ecb5a046e07313e3237b2cf84
Reviewed-on: https://chromium-review.googlesource.com/989424
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#547940}