Updating refs to new space in internal data structures could take some
time, so also measure this.

Bug: chromium:844008
Change-Id: I9f5af4d09f8ef580ca0ad0019cfc78a994d62ffd
Reviewed-on: https://chromium-review.googlesource.com/1128889Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@google.com>
Cr-Commit-Position: refs/heads/master@{#54328}