[Task Migration][Extensions] Migrate the SystemInfo API

Migrate the system info API to use the new task scheduler API
instead of using the worker pool. Note: also change the shutdown
behavior to be SKIP_ON_SHUTDOWN, since there's no reason for it to be
CONTINUE_ON_SHUTDOWN.

Bug: 689520
Change-Id: I4c4fb9990123f6124948b12fc6cf580ec45c8da7
Reviewed-on: https://chromium-review.googlesource.com/591987
Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491194}
2 files changed