Bug 1616901 - Allocate 16 layers for rgba8 linear textures in the cac…
…he and allocate new arrays instead of growing it. r=gw Differential Revision: https://phabricator.services.mozilla.com/D67575 [ghsync] From https://hg.mozilla.org/mozilla-central/rev/622591504941057199af911f1167fa75cd8d8830