commit 4c716e0841542e71c2522f9b8544250e5da2da2c
author Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com> Fri Oct 04 19:11:42 2024
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Oct 04 19:11:42 2024
tree 013a516be57eb350d2209e3c34cdcb51397e8974
parent c3d3721408a16dad2203c99b2681d93725985c9b

compute pressure: Ignore std::nullopt samples in CpuProbeManager

CpuProbes can produce std::nullopt samples when a value when an invalid
value is retrieved from the platform or, in the case of a fake probe (be
it system_cpu::FakeCpuProbe or the virtual probes used by WebDriver),
when CpuProbeManager starts asking for samples before a fake value has
been set.

Before this CL, this meant that there was a short window in web tests
between PressureObserver.observe() and update_virtual_pressure_source()
being called where VirtualCpuProbe would call
CpuProbeManager::OnCpuSampleAvailable() with std::nullopt and it would
end up being converted to a "nominal" pressure state, resulting in an
extra, unexpected update being delivered to PressureObserver that could
cause some web tests to fail.

We now only deliver updates if we got a valid sample from the probe.

Bug: 347031400
Change-Id: I37ae216ee13fff81177f6ddb0fa77fe7910132be
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5907628
Commit-Queue: Raphael Kubo Da Costa <raphael.kubo.da.costa@intel.com>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1364385}