Fix flakiness in CpuTimeSleepy Looks like we can't really rely on the direct wall comparison---probably different resolutions are tripping us up here. Bug: chromium:1272977 Change-Id: Ie3691c59eb5b3765b79f1861200436d9c5acd609 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3313481 Commit-Queue: Lingfeng Yang <lfy@google.com> Reviewed-by: Charlie Lao <cclao@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>