Add automatic metadata generation

BUG=chromium:1051691
TEST=emerge and run_tests.sh

Change-Id: I482e2cb4763dd7ac253b537578dad0e0c393f994
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/tnull/+/2298662
Tested-by: Jacob Kopczynski <jkop@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
Commit-Queue: Jacob Kopczynski <jkop@chromium.org>
Auto-Submit: Jacob Kopczynski <jkop@chromium.org>
6 files changed