Add animated webp images to DM testing

Change-Id: Idb6f95574136cbcb4fb45784a5bf1db3fa97ab32
Reviewed-on: https://skia-review.googlesource.com/17832
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
2 files changed