Bug 1623647 - Allocate one screen's worth of picture cache tiles in each direction instead of three. r=gw
Bug 1623647 - Allocate one screen's worth of picture cache tiles in each direction instead of three. r=gw

Differential Revision: https://phabricator.services.mozilla.com/D67559

[ghsync] From https://hg.mozilla.org/mozilla-central/rev/610fe9c88f2e04fc10ce3564b7794d862562fd05

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