Move OpacityFilterCanvas to new API.

The opacity filter canvas always ends up making a copy of the paint when
it is used anyway, so avoid the overhead of keeping track of the copy on
write.

Change-Id: Ib8b2659f5fc2b18da7b8f2e795041da3457fa22d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1565236
Reviewed-by: Mike Klein <mtklein@chromium.org>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Cr-Commit-Position: refs/heads/master@{#650829}
2 files changed