cc: Make DisplayScheduler use later deadline when swap throttled.

cc: Make DisplayScheduler use later deadline when swap throttled.

This makes swap throttling behavior of the DisplayScheduler match
cc::Scheduler.

Using an earlier deadline hurts throughput without necessarily
helping latency. In the future we should have more explicit
latency recovery in the DisplayScheduler - but only when we
know we are fast enough.

BUG=496766
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1230153004

Cr-Commit-Position: refs/heads/master@{#338812}