Bug 1717738 - Fix low-quality pinch-zoom mode with hw-wr r=gfx-reviewers,jnicol
Bug 1717738 - Fix low-quality pinch-zoom mode with hw-wr r=gfx-reviewers,jnicol

Fixes a case where at the end of a pinch-zoom on the Draw compositor
the tiles would be drawn incorrectly (due to the transforms not
being quite right for the local-to-surface case here, which was
affecting the occlusion calculations).

Differential Revision: https://phabricator.services.mozilla.com/D118559

[ghsync] From https://hg.mozilla.org/mozilla-central/rev/cebda231c6429edabf3ef130e0c1e2214ad7c18c

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