Basically we always scale up, rather than scale width, which is what the
spec was changed to require about a year ago.

BUG=606039

Change-Id: Iebfed41771a5b11bad6daf3655de750cce4c6cf8
Reviewed-on: https://chromium-review.googlesource.com/813201Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Commit-Queue: Ted Meyer <tmathmeyer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523683}