Update flags before recalculating outcomes.

Bug: v8:6917
Change-Id: I5f54f7d14fd60f7e35a976e5200d3f7f0e74a5b7
Cq-Include-Trybots: luci.v8.try:v8_linux64_fyi_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/876364Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michał Majewski <majeski@google.com>
Cr-Commit-Position: refs/heads/master@{#50731}