Drop win7-rel to a 10% CQ experiment.

The bot was unable to recover overnight. Removing it from the CQ
to allow it to do so & allow us to fix any remaining issues affecting
its cycle time.

Bug: 943372
Change-Id: I52bbfba7fc0d266ebd7dd364bd4b5eea84d8df18
Tbr: martiniss@chromium.org
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1529619
Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641855}
2 files changed