Bug 1608280 - Support a per-tile clip (valid) region for compositor t…
b25c1f8
…iles r=nical Differential Revision: https://phabricator.services.mozilla.com/D59437 [ghsync] From https://hg.mozilla.org/mozilla-central/rev/7295ca89e880c1c930643e72ff0600cb71cebb9e
