Also updated test color values to be "valid". The previous set were
intended to be premul-rgba, but they were not legal premul. The new
values are SkColor values, which are defined to be unpremul.

Bug: 896969
Change-Id: Iebaf94ab767d2622798a239a4714ac4b64613225
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2053257Reviewed-by: weiliangc <weiliangc@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
Cr-Commit-Position: refs/heads/master@{#741541}