Bug 1642629 - Reduce the amount of vector reallocation when adding primitives to batches. r=gw
Bug 1642629 - Reduce the amount of vector reallocation when adding primitives to batches. r=gw

Differential Revision: https://phabricator.services.mozilla.com/D79277

[ghsync] From https://hg.mozilla.org/mozilla-central/rev/055e358cab6c1ba4f5b53b684680224246c6f7f0

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