commit 48a6f4fc32d0027102b2217b4ce9139b27e9a192
author Joe Mason <joenotcharles@google.com> Thu Nov 09 04:42:03 2023
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Nov 09 04:42:03 2023
tree 4448bd2ba30b7910cacfd669ad46ef909c6f6ba7
parent 1e601cd8bfaa6f300a17da032fdcd6701676da8f

Reland "Log system PageIntervention.CPU histograms"

This is a reland of commit 2e36357fed4bd2ff66969a700579a5bc0a15a4c1

It checks the system CPU before the page CPU, since PageNode's in the
page CPU result vector might be deleted during the asynchronous system
CPU probe lookup.

Also adds a histogram that's logged when there's an OS error reading
the system CPU, and updates the unit test to expect either the
system CPU histograms or the error histogram.

Original change's description:
> Log system PageIntervention.CPU histograms
>
> Reworking of https://crrev.com/c/4986211 to query the page and system
> CPU usage in sequence instead of in parallel, which avoids a lot of
> complicated callback code.
>
> Also adds a sequence checker to PageTimelineMonitor to ensure the
> system CPUProbe is always invoked from the right sequence.
>
> R=agale
>
> Bug: 1481051
> Change-Id: I2d60a2938ac00aadd9a0634632aba96252ca2ef5
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5006571
> Commit-Queue: Joe Mason <joenotcharles@google.com>
> Auto-Submit: Joe Mason <joenotcharles@google.com>
> Reviewed-by: Alison Gale <agale@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1221259}

Bug: 1481051
Change-Id: I6fed5aea06920d189be5cb3eb90e1e83e9c75250
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5013509
Reviewed-by: Alison Gale <agale@chromium.org>
Commit-Queue: Joe Mason <joenotcharles@google.com>
Cr-Commit-Position: refs/heads/main@{#1222080}