Support for polling cgroup information (similar to vmstat/meminfo/process rss)

Hi Perfetto team,

In Android, cgroups are heavily used for resource management, and many subsystems expose useful metrics.

Currently, Perfetto supports polling of metrics like system-wide vmstat, meminfo, and process RSS.

I would like to know if there is any plan to support polling cgroup stats in a similar way.

This would be very helpful for:
- Tracking resource usage for specific task groups (e.g., foreground/background apps, system services)
- Monitoring CPU/memory usage for performance analysis of specific workloads (e.g. top-app, foreground, background)

Is there currently any feasible way to implement cgroup polling in Perfetto?

If not, would you consider supporting it in the future?

Thanks for your great work on Perfetto!

No implementation files or tests are named. Start by comparing the existing vmstat, meminfo, and process RSS polling support, then determine the scope needed for cgroup statistics; done would mean cgroup metrics can be polled for the requested task groups and are covered by appropriate tests.

Written by the indexing model from the issue text.