GitLab

Adds a paint preview compositor service for compositing collections of
SkPictures representing frames into bitmaps. This is very similar
in principle to the PDF compositor service, but produces tileable
bitmaps rather than a PDF.

A client to this service should start the compositing collection
portion of the service in a utility process. The client can then
create and delete dedicated compositor instances for each group of
SkPictures. Realistically only one compositor will be actively
communicating at a time. However, multiple compositors can be
"warm" (data is deserialized and in memory for fast switching).

Bug: 1011430
Change-Id: I21cb594cd94982f8d4fc5800d9ae4d74b5d9973b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1842273Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Reviewed-by: Ian Vollick <vollick@chromium.org>
Reviewed-by: Mehran Mahmoudi <mahmoudi@chromium.org>
Commit-Queue: Calder Kitagawa <ckitagawa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709946}