Some of this logic already existed, but when we optimized
SurfaceFlinger to avoid unnecessary wake-ups, we didn't carry the logic
over into the new readiness test. shouldPresentNow now returns true if
the timestamp is more than a second in the future (since it's likely a
bogus timestamp and should be ignored).
Bug: 21932760
Change-Id: Ib50970a4eb621588c0b60766c8d8d1a8bddf853b