The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/91a26f05e5d9c5a20d1300db1fbe732d8847d805

commit 91a26f05e5d9c5a20d1300db1fbe732d8847d805
Author: Quinten Yearsley <qyearsley@google.com>
Date: Fri Jun 30 15:52:57 2017

rebaseline-cl: Don't try to fetch results for unfinished builds.

This CL changes rebaseline-cl so that it only fetches
results for completed, failed builds.

For completed, successful builds, they should be considered
to have no baselines to download.

For scheduled and started builds, and canceled builds,
there are no usable results (yet), so the tool can prompt
the user to ask if they want to try to continue with
results only for some builders.

Apart from  http://crbug.com/726376  (don't fetch results for
started builds), I believe this should also fix
 http://crbug.com/726855  (don't try to fetch retry results
for started or passing builds).

Bug:  726376 ,  726855 
Change-Id: I2e92a426f10f40c580b3aa9a31974b4489565a77
Reviewed-on: https://chromium-review.googlesource.com/548984
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Quinten Yearsley <qyearsley@chromium.org>
Cr-Commit-Position: refs/heads/master@{#483714}
[modify] https://crrev.com/91a26f05e5d9c5a20d1300db1fbe732d8847d805/third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl.py
[modify] https://crrev.com/91a26f05e5d9c5a20d1300db1fbe732d8847d805/third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl_unittest.py

Should be fixed now, planning to verify (by running webkit-patch rebaseline-cl on a CL that has some started/scheduled/passed jobs).