What is slice wait time?  Is it different than Pending time?

Each TaskSlice has its own expiration_secs value. It is currently only displayed in the "Task Timing Information" but not for each task slice.

The Expires in the Task Timing Information updates based on which slice is shown.  

You'll notice it's different on the linked task between slice 1 and slice 2.

Oh, I think it's confusing, I didn't personally realize the value was changing.

I'd recommend to have the overall expiration in the Task Timing Information section that does not update, and individual value in each slice.

Which value goes in that Task Timing Information then?  I thought that came from the slices?

It should be the sum of all expiration_secs values.

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/luci/luci-py.git/+/fd39e646d17c4628ee8c96eec75d5baa509f273a

commit fd39e646d17c4628ee8c96eec75d5baa509f273a
Author: Kevin Lubick <kjlubick@google.com>
Date: Tue Sep 25 12:56:02 2018

Fix expiration time for task slices

Bug:  887617 
Change-Id: I3a54b8de6ceb036296cccf84b700aad761ec71a3
Reviewed-on: https://chromium-review.googlesource.com/1240953
Reviewed-by: Marc-Antoine Ruel <maruel@chromium.org>
Commit-Queue: Marc-Antoine Ruel <maruel@chromium.org>
Auto-Submit: Kevin Lubick <kjlubick@chromium.org>

[modify] https://crrev.com/fd39e646d17c4628ee8c96eec75d5baa509f273a/appengine/swarming/ui/build/elements.html
[modify] https://crrev.com/fd39e646d17c4628ee8c96eec75d5baa509f273a/appengine/swarming/ui/res/imp/taskpage/task-page.html

Deployed and confirmed. Thanks!