commit c5f0b267cc02c559f539f63abbc5a8939e9babda
author Chris Hamilton <chrisha@chromium.org> Fri May 24 18:00:32 2019
committer Commit Bot <commit-bot@chromium.org> Fri May 24 18:00:32 2019
tree 7f73639413a848635466b99e87227cbdb937c527
parent e684fa2fb2f2d9d74fd1dc1349c86b02942ffb8f

[PM] Add IsolationContextMetrics.

The BrowsingInstance ByTime metric will allow us to determine how often
sites are alone in a browsing instance, while the PageTime variant will
allow us to estimate how much more impact freezing can have when
browing instance data is explicitly taken into account.

The FrameSiteInstanceProcessRelationship metrics are for estimating
possible impact of Blink Isolates. The ByProcess metric will let us
estimate how many processes will end up having to host multiple frames
in one isolate, when the ByTime metric allows us to estimate the
percentage of time a process spends hosting frames with a shared site
instance.

BUG=960924

Change-Id: Ia53cf5eddc74c8c2d7a825c49fe9b50a1685e147
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1603767
Commit-Queue: Chris Hamilton <chrisha@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663159}