enable SKP rendering on 2 platforms, 2 configs each

The presence of the expectations file (even if empty) causes the bots to render the SKPs and record results.

2 platforms, 2 configs each should be good for exercising rebaselining tools.

BUG=skia:1942
NOTRY=true
R=rmistry@google.com
TBR=rmistry

Author: epoger@google.com

Review URL: https://codereview.chromium.org/426023002
3 files changed