Bug 1516568 - Fuzz a couple of mac reftests. r=gw
Bug 1516568 - Fuzz a couple of mac reftests. r=gw

For some reason running these via cross-compiled wrench in Mozilla
automation produces a few pixels difference.

Differential Revision: https://phabricator.services.mozilla.com/D19368

[wrupdater] From https://hg.mozilla.org/mozilla-central/rev/f06721b552a819e4d2456f1c31d62c782d9a42cb

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