Bug 1762516 - Add `map_point` to `SpaceMapper` r=gfx-reviewers,lsalzman
Bug 1762516 - Add `map_point` to `SpaceMapper` r=gfx-reviewers,lsalzman

Differential Revision: https://phabricator.services.mozilla.com/D142642

[ghsync] From https://hg.mozilla.org/mozilla-central/rev/b551e8753d00d387da6ef503a87216ad57082af8

servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender