Bug 1565910 - Preserve batch features when merging batches. r=gw
Bug 1565910 - Preserve batch features when merging batches. r=gw

Differential Revision: https://phabricator.services.mozilla.com/D38080

[wrupdater] From https://hg.mozilla.org/mozilla-central/rev/f86fb2490cfa53bfecd250c01d1d391a14f73342

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