docs: Noted how to get LOG(INFO) messages

Noted how to get LOG(INFO) messages on Chrome OS, if desired

BUG=none
TEST=none
R=derat@chromium.org

Change-Id: I761d5ea6b69aa3ecee6aa6b0882384dd91ca328d
Reviewed-on: https://chromium-review.googlesource.com/c/1395722
Reviewed-by: Dan Erat <derat@chromium.org>
Commit-Queue: Ian Barkley-Yeung <iby@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620024}

docs/chrome_os_logging.md

@@ -27,14 +27,16 @@ determining when or why Chrome started or stopped.
 By default, only messages logged at severity `WARNING` or higher are written to
 disk. More concretely, `LOG(INFO)` messages are discarded.
 
-## Verbose Logging
-
-When actively debugging issues, Chrome's `--vmodule` flag is sometimes used to
-temporarily log messages at lower severities for particular modules. See the
+To enable `LOG(INFO)` message, pass `--log-level=0` to Chrome. See the
 [Passing Chrome flags from session_manager] document for more details, and
 specifically the `/etc/chrome_dev.conf` mechanism that can be used to
 change flags on development devices.
 
+## Verbose Logging
+
+When actively debugging issues, Chrome's `--vmodule` flag is sometimes used to
+temporarily log messages at lower severities for particular modules.
+
 [base/logging.h]: ../base/logging.h
 [session_manager]: https://chromium.googlesource.com/chromiumos/platform2/+/master/login_manager/
 [Passing Chrome flags from session_manager]: https://chromium.googlesource.com/chromiumos/platform2/+/master/login_manager/docs/flags.md