GitLab

To investigate crbug.com/1132866 this CL introduces a metric on how much
time is spent on serializing the preferences into a string. This time is
critical as it happens on the UI sequence.

Bug: 1132866
Change-Id: Ib514f45b55cdc0d04feec2251d1ae2a2d7e117b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2562184Reviewed-by: Gabriel Charette <gab@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Dominic Battré <battre@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833004}