- small anti-alias effect difference of texts, rounded borders
- rounding difference of opacity
- invisible gradient differences
- mask-with-added-filters.html is a SPv2 progression.

Change-Id: I0bc0dbe84e586d7a89f7f27da55e1e5fffd6119a
Reviewed-on: https://chromium-review.googlesource.com/c/1305890
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604785}