Bug 1522017 - Clip picture caching debug display to avoid overflowing the browser chrome. r=gw
Bug 1522017 - Clip picture caching debug display to avoid overflowing the browser chrome. r=gw

Differential Revision: https://phabricator.services.mozilla.com/D17436

[wrupdater] From https://hg.mozilla.org/mozilla-central/rev/44febac9160b71d7b9317d09e7ff7a3f4bc8c46f

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