A simple gradient test

Change-Id: Ic3e53f7eab747f63641e0eb6a1c73ad0833acef6
Reviewed-on: https://skia-review.googlesource.com/8158
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Tenghui Zhu <ztenghui@google.com>
2 files changed