Add second Store Debug Logs button, with user logs

On Chrome OS some logs are stored in /var/log, some other (warnings and
lower during user session) — only in /home/chronos/user/logs. Button
“Store Debug Logs” on chrome://net-internals#chromeos creates an archive
only with logs from /var/log.

New button next to old one creates similar archive, but includes logs
from /home/chronos/user/logs as well.

Bug: 904600
Bug: 917700
Change-Id: I58f80dd1a347eee0f88718a950e185cfedb59cf4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1494454
Commit-Queue: Oleg Davydov <burunduk@chromium.org>
Reviewed-by: Eric Roman <eroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#639949}
4 files changed