GitLab

At first, this class will own the performance_monitor::SystemMonitor.

In the future, it will also own the ProcessMonitor when it no longer
is a leaky singleton.

Bug: 1166820
Change-Id: Ie47865c3b6e9afcae91be14c22342f3b27685426
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2630228Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Reviewed-by: Sébastien Marchand <sebmarchand@chromium.org>
Commit-Queue: Patrick Monette <pmonette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844571}