The failures already have been there: https://treeherder.mozilla.org/#/jobs?repo=try&revision=3d6cc94f2db7a2e55f41405ef0575102637e0633&selectedTaskRun=ZUj4QROIQo6nGympvvqvjA.0 ... but they only fail inside a job "geckoview-test-verify" and the job even does not always runs the test. It makes hard to track the initial failure, so this patch just allows subpixel difference. Differential Revision: https://phabricator.services.mozilla.com/D86486