GitLab

The provider reports number of files currently being monitored by
the watcher. This is needed to confirm there's no memory leak in the
SharedFileWatcher.

BUG=810155

Change-Id: I560a4ce8c7a297cd60162c528e8c76c37f3a47ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1539017Reviewed-by: ssid <ssid@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Alexei Filippov <alph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#644387}