The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/619e356507bb7c8f8e39981f662117af591f6cfa

commit 619e356507bb7c8f8e39981f662117af591f6cfa
Author: juliatuttle <juliatuttle@chromium.org>
Date: Fri Nov 04 23:10:46 2016

Domain Reliability: Expire queued beacons after 1 hour.

This isn't perfect -- it doesn't reschedule uploads when beacons expire,
and it assumes beacon start times are roughly in increasing order -- but
it should get the job done.

(The imperfections may result in it uploading the beacon *after* an
expired one slightly early, or uploading an expired beacon because it
started before but ended after an unexpired beacon that therefore ended
up *before* it in the queue.)

(A more thorough version of this would keep an explicit "queued time"
field, but I'm hoping to merge this, so I want the simplest working
solution.)

BUG= 661632 

Review-Url: https://codereview.chromium.org/2464163003
Cr-Commit-Position: refs/heads/master@{#430060}

[modify] https://crrev.com/619e356507bb7c8f8e39981f662117af591f6cfa/components/domain_reliability/context.cc
[modify] https://crrev.com/619e356507bb7c8f8e39981f662117af591f6cfa/components/domain_reliability/context.h
[modify] https://crrev.com/619e356507bb7c8f8e39981f662117af591f6cfa/components/domain_reliability/context_unittest.cc